You still gotta buy
rear axle complete ($400 average)
I won't argue that. That's about what I paid. I'd have gotten it for less if I needed 3.73 gears, but 3.42
and G80 was tougher to find.
Rebuild kit for axle ($200)
Ring and pinion kit ($250)
installation of kits labor ($800)
Installation of the axle labor ($400)
Select a good axle, you don't rebuild it.
Don't buy a ring and pinion kit, because you're not dicking with the pinion. He'd need a pair of side bearings, and perhaps some shims. He'd need access to a dial indicator to measure backlash, which is probably available as a loaner-tool.
And, yes, I expect him to install the posi carrier, and axle himself. If he doesn't have a decent, ACCURATE torque wrench, he shouldn't be on this site.
Ubolts ($40)
Possibly joints ($30)
I think you may be low on the U-bolts, but he only needs the rear U-joint. $70 is probably not far from the truth.
Front rotors ($140)
Brake pads (60)
Wheels ($600
Tires ($600)
Get the rotors, pads, wheels and tires from the truck that's donating the axle. Or at least, from the same Treasure Yard. I bet he gets everything he needs for a grand--including the axle.
If you diy you need tools to set up the axles, calipers, dial guage, torque wrench, gear oil, brake fluid, seal puller and drivers, bearing puller and driver, shop press for the carrier etc.
The press to install the carrier bearings might be a genuine consideration. He'd maybe have to pay a shop to press the bearings.
The rest is pretty tame.
Some of this really does depend on finding a suitable donor vehicle; or a Treasure Yard that will work with him to sell a "package deal". I looked a long time for a suitable axle; but
I wanted an axle I didn't have to change carriers on; and Gov-Lock was just fine with me in a 9.5 axle, where it wouldn't be in an 8.5.
OTOH, I'll be doing a carrier upgrade on my '97 K2500 (10.5 axle) this summer. Who the hell buys a truck to plow snow, and
doesn't check the box for a locking rear axle? So again, I'm not planning to rebuild the axle. I'm going to push bearings onto a new carrier, transfer the ring gear, match the backlash, and torque the caps. The pinion doesn't leak, and I'm not going to touch it.
I will inspect the brakes while the axle shafts are out--being a full-float axle, getting the drums off requires a heap of work that doesn't need to be done on an 8.5 or 9.5 axle.