buying bulk 48 hour codes...low priced and reputable supplier needed

I spend anywhere from 20-30 $ a week buying xbl 48 hr codes but my guy is tryin to up the price to 20 cents a piece (second time he's tryed this) anyway im lookin around tryin to find a supplier and by supplier i dont mean someone who has a couple hundred codes to give out. I need someone with thousands of codes that arent posted up for all the public to c. if you can do a good deal or know someone who i should talk to then please pm me. like i said, i can get them all day for 20 a piece so it would have to be alot lower than that. Thanks!