Trade

Trading refers to the buying and selling of goods. In the SCA a trade may refer to the bartering of goods.

Often people will trade items based one their cost and the time it took to make. So, for example, you might be good at leatherwork and your friend might be good at sewing. You buy a tabard from your friend for the cost of matierials and the time it took to make. The other person can then "use" the time you paid to have a new leather belt made (plus the cost of materials of course).