If you can bring your own parts you could save as much as 20-50% on that portion of the bill. Most parts stores will sell to the public for nearly the same price as they sell to the shop.
The shops will argue that they can't warranty the work unless they provide the parts, but I'm more interested in saving the money so I usually get my own parts. You can also get used parts for much less at Transwest in Lehi or LKQ in Springville.