But the harm may go deeper than a mistaken view of human psychology. According to Graeber, once one assigns specific values to objects, as one does in a money-based economy, it becomes all too easy to assign value to people, perhaps not creating but at least enabling institutions such as slavery (in which people can be bought) and imperialism (which is made possible by a system that can feed and pay soldiers fighting far from their homes).

Men from the visiting group sit quietly while women of the opposite moiety come over and give them cloth, hit them, and invite them to copulate. They take any liberty they choose with the men, amid amusement and applause, while the singing and dancing continue. Women try to undo the men’s loin coverings or touch their penises, and to drag them from the “ring place” for coitus. The men go with their … partners, with a show of reluctance to copulate in the bushes away from the fires which light up the dancers. They may give the women tobacco or beads. When the women return, they give part of this tobacco to their own husbands.
With 8.5 million members and 5,000 groups, Freecycle is like the mother of all garage sales, with one exception: Everything is free! The site started as a grassroots organization, encouraging members to reuse products rather than send them out to the landfills. For example, I have used Freecycle many times to find new owners for pieces of my cassette and record collection, piles of magazines and books, and assorted unneeded tools.
Freegans are people who embrace community and sharing, in opposition to a society based on materialism and greed. Freegans avoid purchasing new products or food as much as possible. Instead, they spend a lot of time digging through trash and waste, looking for the things they need. Yes, it’s an extreme example of sharing and bartering, but they make the system work for them!
No academics I talked to were aware of any evidence that barter was actually the precursor to money, despite the story’s prevalence in economics textbooks and the public’s consciousness. Some argue that no one ever believed barter was real to begin with—the idea was a crude model used to simplify the context of modern economic systems, not a real theory about past ones.
So as you consider items to stockpile, you should think about items that are necessary, but might not take up a lot of space.  Referring back to Mark Goodwin’s book mentioned above, one thing the main characters looked for were canning lids and rings.  They don’t take up a lot of space and in a real collapse situation, they will be really worth it!
While one-to-one bartering is practiced between individuals and businesses on an informal basis, organized barter exchanges have developed to conduct third party bartering which helps overcome some of the limitations of barter. A barter exchange operates as a broker and bank in which each participating member has an account that is debited when purchases are made, and credited when sales are made.
Identify your resources. What items do you have that you could easily part with? Use a critical eye to go through your home, and consider possessions you may have in storage or that another family member or friend is currently using. If you would prefer to offer services, honestly assess what you could provide for others that they would otherwise pay a professional to do. It could be a skill or a talent or hobby such as photography.  

Economists since the times of Adam Smith (1723-1790), looking at non-specific pre-modern societies as examples, have used the inefficiency of barter to explain the emergence of money, of "the" economy, and hence of the discipline of economics itself.[3] However, ethnographic studies have shown that no present or past society has used barter without any other medium of exchange or measurement, nor have anthropologists found evidence that money emerged from barter, instead finding that gift-giving (credit extended on a personal basis with an inter-personal balance maintained over the long term) was the most usual means of exchange of goods and services.[4]
Then again, it’s one thing to keep a community alive and well when everyone’s camping in a forest and they’ve all opted in to that vision. It’s quite another to imagine a gift economy enabling humans to build skyscrapers, invent iPhones, put air conditioners in every house, and explore space. (The same goes for collecting taxes and running large businesses.) Not that it’s an all-or-nothing situation: We already have gift economies among friends and family. Perhaps expanding that within small communities is possible; it’s certainly desirable.
Can you make home or vehicle repairs?  Do you manufacture pieces that may be needed for repair?  Can you grow fruit and vegetables and gather the seeds to sell?  Do you sew, knit and repair clothing?  Think through what you can do.  Many skills that preppers have are taken for granted by others.  The skills that you have that seem like common sense to you could keep you and your family fed in hard times.
@matthewc23 - I love being able to barter for things. You mentioned that you don't really have any specialized skills, but you would be surprised. Depending on your profession, think about any special training you have that a normal person wouldn't have. Some people would be willing to trade for that service. Even things you wouldn't normally think of as being services could be useful to someone else.

Unlike one-on-one bartering, members of exchanges are not obligated to barter or purchase directly from a seller. Instead, when a barter exchange member sells a product or a service to another member, their barter account is credited for the fair market value of the sale. When a barter exchange member buys, the account is debited for the fair market value of the purchase.

Can you make home or vehicle repairs?  Do you manufacture pieces that may be needed for repair?  Can you grow fruit and vegetables and gather the seeds to sell?  Do you sew, knit and repair clothing?  Think through what you can do.  Many skills that preppers have are taken for granted by others.  The skills that you have that seem like common sense to you could keep you and your family fed in hard times.
mid-15c., apparently from Old French barater "to barter, cheat, deceive, haggle" (also, "to have sexual intercourse"), 12c., of uncertain origin, perhaps from a Celtic language (cf. Irish brath "treachery"). Connection between "trading" and "cheating" exists in several languages. Related: Bartered; bartering. The noun is first recorded 1590s, from the verb.
Whether or not one agrees with such broad claims, it’s worth noting that monetary debt, a byproduct of currency, has regularly been used to by some groups to manipulate others. Thomas Jefferson, for instance, suggested that the government encourage Native Americans to purchase goods on credit so they’d fall into debt and be forced to sell their lands. Today, black neighborhoods are disproportionately plagued by debt-collection lawsuits. Even after taking income into account, debt collection suits are twice as common in black neighborhoods as in white ones. $34 million was seized from residents of St. Louis’ mostly black neighborhoods in suits filed between 2008 and 2012, much of which was seized from debtors’ paychecks. In Jennings, a St. Louis suburb, there was one suit for every four residents during those years.
Like in Venezuela, people are bartering for needs.  The important things that are sought right now seem to be food and medicine.  But at some point, people will be wanting a “taste” of their former life.  They will want something that reminds them of the life they had.  It could be as simple as a piece of chocolate or a nice new dress.  The important thing here will be timing, security, and perception.
If you need more than clothes, like baby bedding, baby furniture, or even sporting goods, you’ll be glad to find Zwaggle. It’s a network of parents who have joined together to share the expense of getting “new to your family” stuff in exchange for used or no-longer-needed items. You receive Zwaggle points for giving away your things, and you can use those points to get the things you want. Membership is free, and the community is powered by a points system rather than cash. The only money you have to spend is on shipping.
Adam Smith, the father of modern economics, sought to demonstrate that markets (and economies) pre-existed the state, and hence should be free of government regulation[citation needed]. He argued (against conventional wisdom) that money was not the creation of governments. Markets emerged, in his view, out of the division of labour, by which individuals began to specialize in specific crafts and hence had to depend on others for subsistence goods. These goods were first exchanged by barter. Specialization depended on trade, but was hindered by the "double coincidence of wants" which barter requires, i.e., for the exchange to occur, each participant must want what the other has. To complete this hypothetical history, craftsmen would stockpile one particular good, be it salt or metal, that they thought no one would refuse. This is the origin of money according to Smith. Money, as a universally desired medium of exchange, allows each half of the transaction to be separated.[3] 

Need a ride? Zimride is a ride share service which members use to set up private networks for sharing rides and saving money. Most cars fit four people, yet we usually commute by ourselves. Why not share the burden of car ownership and resource consumption? Centered around hundreds of colleges and universities, you can probably find a ride almost anywhere you need to go near campus.
PaperBack Swap is exactly what it sounds like: a place to swap paperback books. Currently, more than half a billion books are available for trade on the site. Just list the books you don’t want anymore and other members will find them. When someone requests one of your books, you just mail it out and then choose any available book that you want to receive. Swapping is easy, and membership is free.
When two people each have items the other wants, both people can determine the values of the items and provide the amount that results in an optimal allocation of resources. Therefore, if an individual has 20 pounds of rice that he values at $10, he can exchange it with another individual who needs rice and who has something that the individual wants that's valued at $10. A person can also exchange an item for something that the individual does not need because there is a ready market to dispose of that item.