Trade in Skyrim is oversimplified and uninteresting. A particular type of merchant always has the same amount of gold and offers you the exact same prices as the same type of merchant in another part of the country. Merchants in small towns differ very little from those in the larger cities, and the only factors that affect price are your speech skill and any barter enchantments you might have.
The Owenite socialists in Britain and the United States in the 1830s were the first to attempt to organize barter exchanges. Owenism developed a "theory of equitable exchange" as a critique of the exploitative wage relationship between capitalist and labourer, by which all profit accrued to the capitalist. To counteract the uneven playing field between employers and employed, they proposed "schemes of labour notes based on labour time, thus institutionalizing Owen's demand that human labour, not money, be made the standard of value." This alternate currency eliminated price variability between markets, as well as the role of merchants who bought low and sold high. The system arose in a period where paper currency was an innovation. Paper currency was an IOU circulated by a bank (a promise to pay, not a payment in itself). Both merchants and an unstable paper currency created difficulties for direct producers.
Barter, the direct exchange of goods or services—without an intervening medium of exchange or money—either according to established rates of exchange or by bargaining. It is considered the oldest form of commerce. Barter is common among traditional societies, particularly in those communities with some developed form of market. Goods may be bartered within a group as well as between groups, although gift exchange probably accounts for most intragroup trade, particularly in small and relatively simple societies. Where barter and gift exchange coexist, the simple barter of ordinary household items or food is distinguished from ceremonial exchange (such as a potlatch), which serves purposes other than purely economic ones.
BizXchange is for business-to-business barter, where members use “BizX dollars” to help each other save cash on expenses and find new ways to grow their businesses. BizX dollars are earned by (and can be spent on) selling products, services, or unused inventory to other members. Membership costs include a one-time initiation fee of $795, a $15 cash/$15 BizX monthly fee, and a 6% fee on each transaction with other members.
Other countries, though, do not have the reporting requirement that the U.S. does concerning proceeds from barter transactions, but taxation is handled the same way as a cash transaction. If one barters for a profit, one pays the appropriate tax; if one generates a loss in the transaction, they have a loss. Bartering for business is also taxed accordingly as business income or business expense. Many barter exchanges require that one register as a business.