Just depends on what you want to replace. Are you going to rebuild the t-lock?
If you just want to do the minimum, then I would get the FRPP gears from ebay (got mine brand new for $140), then buy a differential shaft locking bolt ($5 @ NAPA) & some friction modifier ($8 @ FORD).
If any of the bearings are bad, then they can get autozone to drive the parts over to them. They are cheap.
That is all I can think of. My brother paid $250 for the installation on his 03 GT.
But if I was you, I would spray the ABS sensors with penetrating oil the night before, because shops don't usually do that, and when they break the ABS sensors & you get charged for it.
When I did my gears, the ABS sensors came out like butter. I know the penetrating oil help a lot!
Scott