Bartering does have its limitations. Many bigger (i.e., chain) businesses will not entertain the idea and even smaller organizations may limit the amount of goods or services for which they will barter (i.e., they may not agree to a 100% barter arrangement and instead require that you make at least partial payment). But in an economic crunch, bartering can be a great way to get the goods and services you need without having to pull money out of your pocket.
A barber in the countryside cuts hair for yuccas, bananas or eggs. Moto-taxi drivers will get you where you need to go for carton of cigarettes. The owners of one of my favorite Mexican restaurants offer a plate of burritos, enchiladas, tamal and tacos in return for a few packages of paper napkins. At a fast-food joint near my office, the guy working the register let me walk away with a carry-out order of chicken, rice and vegetables without paying the other day, relying on my promise to come back with the 800,000 bolivars.
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.