replacing ABS brake unit and "ABS light" bulb on a 95 YUKON??

[rrpearsall]

I have a 1995 GMC Yukon and I recently noticed my ABS brakes didn't work when I came to a quick stop. I went to the dealer to get it checked out and they said my ABS motor is dead and it would cost me $503 for the ABS unit with $375 in labor!! They also said they may need to replace the EBCM too and that would run me $569 with $78 in labor! I am planning on selling my car ASAP and I definitely can't afford that cost. I have been calling around to get used ABS prices and found some in a salvage yard with the EBCM for $150 - $250 and found mechanics who said they would replace it for $100. I have never bought a used part from an auto salvage place, I woul hate to purchase an ABS motor and have it not work once installed. I am wondering if it is better to get parts from an internet used or remanufactured auto parts store? Do they warranty their products or allow returns?? If anyone knows of a good site to look for ABS parts, please let me know!

The second part of my question is, my ABS light did not go on to tell me about my failed ABS brakes. The mechanic at the dealership said the sensors and everything else is right and that my bulb must be burned out. Which leads me to ask anyone if it is easy to get inside your dash and replace the bulb yourself? If so, is there anything I need to know before getting my hands dirty trying to replace it?

Thanks -Ryan