It is a high asking price but I bet there is that much $$ into it, in the condition it is in now.
I have more than that in my crew cab w/o paint or body work too. I'd guess the $$ into this breaks down similar to this:
$4k purchase price
$800 - 1k shipping (could be lower)
$6K motor rebuild (lower if not farmed out to machine shop)
$1k trans rebuild
$1.5k wheels and tires
$1k carpet, upholstery, lift kit & other incidentals
No labor included and its in the neighborhood of $15k invested.
Unfortunately, those who sink this much money into these trucks and other older vehicles are the one's who stand to lose the most when it comes time to sell. Owners down the road, after the person who forked over the initial cash outlay, usually end up winning in these scenarios.
1pistol1 - Bummer that you're burned out, but I know it happens. I see from older pics that the truck had type 8 mirrors when you bought it. Where did you get the new mirrors from and how stable are they on the highway?