Selling a blacklisted iphone on ebay?

My older brother is trying to get out of a contract but has an over due bill that he wants to pay. I'm trying to help him for a way out and I thought about selling his phone over ebay. I'm not sure if his phone is actually black listed yet. But his service is off, the phone my brother has goes for $300 and more which should be enough to pay off his bill, and the termination fee (if there's one) and get rid of his phone in one move and the phone will no longer be black listed when the other person has it since I'll pay it off when the buyer pays us for the phone (If that's how it works.)
could I sell a black listed phone, provided that I notify buyers, allow return shipping or whatever in case they feel uneasy about buying it. I have a 100% feedback rating already so that should be helpful with trust

I would call the provider and ask what happens if you pay off the bill. I would guess that they would not have it blacklisted anymore. They want money. If you give them money, they should be happy.

Blacklisted phones in the US are almost impossible to get off once on. Actually cleaning the IMEI is illegal. So US value is not what you think it is. Try selling overseas. That's where most phones like that go anyway and they might pay what you are wanting. Best luck.

Make sure you list it as "blacklisted" so the buyer knows (you will get far less $), otherwise they may show up at your door with a baseball bat.