I have a am/fm radio in my 04' and want to put a factory CD player in it, but a new factory player is $375... I was wondering what model year CD player will work in my 04' and if possible, anyone have one they want to sell me??

If you're familiar with eBay, that would be a great place to look for a cd player. There are usually quite a few on there that would work with your truck. You'll need one from an '03 or '04 GM truck or suv, & you'll have to take it to your dealer to have it calibrated to match your VIN.