If he can scrap together the money to buy a Madone, he can pay rent. He needs to go. Set a date, Jan 15 sounds good. Tell him he has to find another place to live, another couch to sleep on, then have the landlord change the locks.

He's not going to move out under his own volition. Unfortunately you're going to have to force the issue. He'll try to linger as long as you'll let him. So you're going to have to be tough if you really want him out.