Auto repair shop that accepts parts you buy

So I know this is a long shot but I figured someone knows of a repair place that accepts parts you buy. I need a new power steering control module for my car and both shops that i've looked at are charging a thousand dollars for the part. I found the same part at the GM dealer for half the price. Wondering if there's any legitimate(and good) auto repair place that has no problem accepting the parts brought to them from the customer.