When small describes how his customers choose to purchase his clothes (by evaluating that his brand is environmentally conscientious, whereas most other brands are not), which condition of exchange is being met?

The condition of exchange that is being met when Small describes how his customers choose to purchase his clothes (by evaluating that his brand is environmentally conscientious, whereas most other brands are not) is that each party believes it is appropriate or desirable to deal with the other party.