Can you teach a skill like canning or cooking from scratch?  Food staples will be more readily available than the processed food many are used to buying at the grocery store and fast food.  And although many in the preparedness community know how to can and cook from scratch, your common everyday American doesn’t.  They wouldn’t know what to do with flour, eggs, and a little oil.
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. 

Many prepper fiction novels eventually get to a point where there is a barter economy or the characters visit a Trading Post.  For instance, a trading post plays a prominent role in Mark Goodwin’s series, Seven Cows, Ugly and Gaunt: A Post-Apocalyptic Saga of America’s Worst Nightmare.  In the novel, the characters use silver to purchase the necessary items to survive and make life easier.  Goodwin’s novel is a post-apocalyptic EMP story.  The poop has really hit the fan in this one!
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]
It’s hard to answer that without actually seeing a modern gift economy in action. Luckily, modern gift economies actually do exist. On a small scale, they exist among friends, who might lend each other a vacuum or a cup of flour. There’s even an example of a gift economy on a much larger scale, albeit one that’s not always in operation: The Rainbow Gathering, an annual festival in which about 10,000 people gather for a month in the woods (it rotates among various national forests around the country each year) and agree not to bring any money. Groups of attendees set up “kitchens,” in which they prepare and serve food for thousands of people every day, all for free. Classical economists might guess that people would take advantage of such a system, but, sure enough, everyone is fed, and the people who don’t cook play music, set up trails, teach classes, gather firewood, and perform in plays, among other things.

Other anthropologists have questioned whether barter is typically between "total" strangers, a form of barter known as "silent trade". Silent trade, also called silent barter, dumb barter ("dumb" here used in its old meaning of "mute"), or depot trade, is a method by which traders who cannot speak each other's language can trade without talking. However, Benjamin Orlove has shown that while barter occurs through "silent trade" (between strangers), it also occurs in commercial markets as well. "Because barter is a difficult way of conducting trade, it will occur only where there are strong institutional constraints on the use of money or where the barter symbolically denotes a special social relationship and is used in well-defined conditions. To sum up, multipurpose money in markets is like lubrication for machines - necessary for the most efficient function, but not necessary for the existence of the market itself."[13]
It is said that “Necessity is the Mother of Invention.”  If we ever get to a point where a barter economy is the way goods and services are exchanged, things will come together.  But those who are prepared ahead of time, those who have thought about all of this, will be in a place where they can quickly move to make decisions that will benefit themselves and their family financially.