The same thing holds true of all other possessions; for barter, in general, had its original beginning in nature, some men having a surplus, others too little of what was necessary for them: hence it is evident, that the selling provisions for money is not according to the natural use of things; for they were obliged to use barter for those things which they wanted; but it is plain that barter could have no place in the first, that is to say, in family society; but must have begun when the number of those who composed the community was enlarged: for the first of these had all things in common; but when they came to be separated they were obliged to exchange with each other many different things which both parties wanted.
An alternate currency, denominated in labour time, would prevent profit taking by middlemen; all goods exchanged would be priced only in terms of the amount of labour that went into them as expressed in the maxim 'Cost the limit of price'. It became the basis of exchanges in London, and in America, where the idea was implemented at the New Harmony communal settlement by Josiah Warren in 1826, and in his Cincinnati 'Time store' in 1827. Warren ideas were adopted by other Owenites and currency reformers, even though the labour exchanges were relatively short lived.
The barter system is a type of trade that involves the exchange of goods and services without the use of money as a medium of exchange. Trade, on the other hand, is a broader concept that includes not just the barter system, but also, international trade, commodities trading, currency trading, etc. The main difference between barter and trade is that while barter trade does not involve money, other forms of trade occur with currency used as a medium of exchange. An important point to note is that the invention of trade whether barter or otherwise has developed a useful system under which individuals, businesses and nations can exchange or sell off the products or goods held in excess and purchase or obtain desired products, goods and services. The invention of currency has greatly simplified this process making trade convenient and fair.
In trade, barter (derived from baretor) is a system of exchange where participants in a transaction directly exchange goods or services for other goods or services without using a medium of exchange, such as money. Economists distinguish barter from gift economies in many ways; barter, for example, features immediate reciprocal exchange, not delayed in time. Barter usually takes place on a bilateral basis, but may be multilateral (i.e., mediated through a trade exchange). In most developed countries, barter usually only exists parallel to monetary systems to a very limited extent. Market actors use barter as a replacement for money as the method of exchange in times of monetary crisis, such as when currency becomes unstable (e.g., hyperinflation or a deflationary spiral) or simply unavailable for conducting commerce.
Michael Linton originated the term "local exchange trading system" (LETS) in 1983 and for a time ran the Comox Valley LETSystems in Courtenay, British Columbia. LETS networks use interest-free local credit so direct swaps do not need to be made. For instance, a member may earn credit by doing childcare for one person and spend it later on carpentry with another person in the same network. In LETS, unlike other local currencies, no scrip is issued, but rather transactions are recorded in a central location open to all members. As credit is issued by the network members, for the benefit of the members themselves, LETS are considered mutual credit systems.
Let's say that you want to make it more difficult to make a quick profit from the items you sell. So you decide to increase the barter settings to 10.0 and 6.5. At these settings, you will receive only 10-15% of an item's value (vanilla is 30-50%). However, you'll suddenly discover that the cost to purchase items has skyrocketed to 1000-650% (vanilla purchase costs are 330-200%). Maybe this is exactly what you want. If so, congrats, there's no need for you to mess with the Independent Adjustments. However, if you would like to reduce the purchase price to a more reasonable level, then you can use the Buying Prices adjustment to lower only the buying prices without affecting the selling prices.
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.