How much will microsoft charge you for repair in the 360?

I didn't get the 3 red lights but somethings broken in the inside of my xbox. I don't even know what the hell happened to it because I didnt even use it 3 days ago. But today when I played it for an hour and turned it off, then turned it back on, it wouldn't read any disks. I gave it a rest for 3 hours but nothing. There was still that annoying cracking sound it makes when it reads a disk which isn't normal. I don't have a warranty and even if I did it should've expired by now. So how much will microsoft will charge me if I send it for repair? because I know those guys wouldn't do anything to fix it unless you give them a payment, and I don't want my xbox to end up in the garbage. It would be a waste of money you know.