At 121,000 I've a failing rear carrier bearing. 2X 2.4L SR5

Trying to replace the whole pumpkin as shops don't want to rebuild. Dealer est : $4,500 for
new differential from Toyota installed. I think it's too much. I want to keep this truck which I bought new at the aforementioned dealer in 2003.

 

Just the third or the whole axle? They (whole axle) are fairly common in the BST and wouldn't take but 5 or 6 hours to swap the whole axle.

 

Well... I thought shipping would be too problematical for the whole thing. I've found whole rear units at $600 -$800 shipped
but I insist on the 3:58 ratio. I'm most confident getting the whole new part (4111035270) but found a used one at $350 shipped. Says "certified grade A part from <75,000 mile vehicle"
but not in the written order confirmation. Seems squirrley and too cheap?

A new assembly was shown at one dealer at $1,181 and quoted at another at $1,726.90. I think I'll tell the used dealer I'll only buy if he ships directly to my ASE cert. mechanic for acceptance
with written full ccard refund if we must reject for defect. No go there I'll go ahead and buy the new one.

PS : What is the core value on my old pumpkin complete (if any) ?