I don't know where you live. Round here what you're offering would be around £125-140 a week.
My understanding is if you rent out a room in your house - in which you also live, you can just give someone notice to leave without them being able to take it to court. It's worth checking anyway.
It does rather sound as if he's got a very good deal but, despite that, is inconsiderate in not doing his fair share. It appears he doesn't appreciate his good fortune. I wouldn't be very happy with the new arrangement either and I really think it is reasonable, given that his changed circumstances now impinge too much on your own life and budget, that you ask him to leave.
Gary Glitter programme Tuesday
To think that London, or anywhere else for that matter, does not belong to any one demographic