[MysticCat]

When one is talking one on one with a friend, there may be some point in responding by explaining why the "paying for friends" line is an unfair characterization.

But, in a group situation like you describe, I think the best and most effective response is to completely ignore him. Completely. If he keeps it up, don't argue or try to set him straight -- reply with a dismissive one-liner (like "then I didn't pay enough" or whatever works for you), then continue on with the conversation as though he hadn't said anything. He really doesn't warrant more.