Whenever I have gone to an autoshop I have always asked for the price of parts and the price of labor. I don't mind paying for labor I don't know how to do myself, but I will not sit by and let the mechanic gouge me on the cost of parts. Usually I am able to bring the price down after negotiating with the shop manager or mechanic.

If you already know what you want to have fixed on your car just call the shop and ask for an estimate. In my experience most shops want you to come in and have your car looked at for a fee before they do anything. A quality shop should provide an estimate if you call in.