Still, Adam Smith really did seem to believe barter was real. He writes, “When the division of labour first began to take place, this power of exchanging must frequently have been very much clogged and embarrassed in its operations,” and then goes on to describe the inefficiencies of barter. And Beggs says that many textbooks sloppily seem to endorse this viewpoint. “They sort of use that fairy tale,” he explains.
By default this option is turned off. When you load the mod menu, the value you see displayed is the setting currently in use in your game. The vanilla value is 2.0, so any other number indicates that another mod is already changing this setting. If you decide to turn this option on, than the settings from Trade & Barter will overwrite any changes to this value made by other mods. If at any time you wish to revert the settings back to those made by another mod, simply toggle off this option and reload your game. You will need to reload your game before the changes from Trade & Barter are fully canceled out.

Barter is a system of exchange by which goods or services are directly exchanged for other goods or services without using a medium of exchange, such as money.[1] It is distinguishable from gift economies in that the reciprocal exchange is immediate and not delayed in time. It is usually bilateral, but may be multilateral (i.e., mediated through barter organizations) and usually exists parallel to monetary systems in most developed countries, though to a very limited extent. Barter usually replaces money as the method of exchange in times of monetary crisis, such as when the currency may be either unstable (e.g., hyperinflation or deflationary spiral) or simply unavailable for conducting commerce.

In late 2012, Toronto even got its own spinoff of Trade School, a model that originated in New York in 2010. The Toronto Trade School holds classes—on anything from spoken word to origami flower–making to bicycle maintenance—and invites students to “pay” with an item or service from the teacher’s barter wish list. It has hosted more than 70 classes.
Fluctuating Gold - This option will add an additional random amount of gold to merchant inventories so that merchants don't always have a static amount of gold. This will be added to their base gold, so they will always have at least the base amount available. The random amounts have been set with regard to the vanilla gold amount and won't increase merchant gold drastically above the vanilla amounts.
Variable Merchant Gold - Adds more gold to select merchants. Merchants in major cities will no longer have the same amount of gold as their small-town counterparts. There are three levels with increasingly greater difference between the gold amounts for city & small town merchants. Personally, I would recommend leaving the Base Merchant Gold at vanilla values and choosing one of the Variable settings instead. You can stack the Variable settings by selecting multiple options in order to get even greater increases in merchant gold, but I really don't recommend doing this as I haven't balanced the values with this intention.
In trade, barter (derived from baretor[1]) 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.[2] 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. 

Yes…yes…yes! When I went to school to become a Registered Massage Therapist, and discovering how difficult it (still) is for a male RMT to get a legit job be it here or a small town, our instructor told us to consider bartering whenever possible. This was in a smaller city (100,000) where bartering can do well for you to make inroads with the Downtown Council, locally owned businesses; let’s say for example a new yoga studio or health club or salon is opening. I bring my massage chair over and do free 10 minute chair massages and give out my business card, in exchange, the yoga groups can use my space if they need to add an extra class. The salon knows if they’re doing a training on a day I’m not working, they can use my studio. Things like that.
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.