Buying something from Chris is the same as buying something from someone, you may disagree with the value of that something, but that doesn't mean he gave Chris money for free.
Value is always seen from the customer's perspective, I know I sold items I completely despise for values I wouldn't ever buy them for, but that's the nature of business overall, demand and value are dictated by the customer.
Chris is someone who surprisingly understands this on a primal, almost-animal level, he lowers the value of items based on how quick it moves (or not), if he was less gullible and more of a people person, he would've been the ideal worker at say, a junkyard or a pawnshop.