The toyota 3rd is relatively easy to regear.. It doesn't take shims in the carrier and is easier to adjust.. The magic is the pinion depth.

Regearing shouldn't run more than $400 or so, including the gears and the labor. Check around pirate 4x4.

If you're being charged $600 for a regear, you're getting screwed.
If you're being charged $1200 for pulling the 3rd and regearing it, you're really getting screwed - for that kind of money I'll work on your rig myself. $1200 for a few hours labor and $300 in parts ain't a bad gig.

Check with the vendors on pirate..