If you rented an apartment for yourself and you can "truly" afford it on your own then all this seems some what suspect. Outside of carpet stains, you mentioned no other damage by your roommate. So I see no reason for you to play hard ball. To be honest your posts come off like your mad he is moving out and now you have to pay the rent by yourself. All this ain't just over some carpet stains, which can be cleaned. So..................................