ATI 5750 Video Card

My video card is failing. I read that in some models the video card is soldered onto the logic board and that in others it snaps out. What is the case for my Late model 2010 (EMC 2390) 27" iMac?

I called a third party service company and they told me that they would rather Apple did the repair. I have read that Apple will charge about $1,100 for this repair. Does anyone have any experience with this sort of repair?

Finally, does anyone know where I can get a compatible replacement? I found a source on the internet that charges about $550 for the card.

Thanks in advance,

Carey