Hey, 6 bucks for some DT +1 ain't a bad deal, maybe we should get into the business

Seriously though, this isn't how the trust system should be used. I'm not sure what recourse you have OP, I'd try sending
philipma1957 a PM about it, since he's the one who has TBZ on his trust list.
I've thought about excluding him before but he technically isn't doing anything wrong by merely leaving a feedback for a trade as that's how the system is meant to be used, but when he does stuff like this it just seems abusive. I honestly don't know whether he knows people are buying his stuff just for the feedback or not but I know that's the only reason people are buying certain things from him, but the problem here lies within the trust system. I think theymos should change it so small deals say under $25 or so carry little to no weight and don't count towards 'green' trust. People are smart enough here to do the right deals with the right people and if you do it's easy to get yourself pretty 'trusted' for about $30-$50.
An exclusion wouldn't really accomplish much either, you would need someone else at level 1 to do the same for it to have an effect.
The way I see it, DT members have an obligation to be more careful with their trust ratings. For instance, positive trust should be given out sparingly, since people tend to assume members with green trust are much more trustworthy. The same is true of negative ratings. Obviously not everyone has the same standards, and people have managed to game the system, like you said.
Speaking of philipma, it looks like his entire trust list is made up of people who have given him positive feedback. Didn't
CanaryInTheMine get removed from level 1 for doing the exact same thing?