Some dudes just don't have the time, knowledge, or desire to hunt down parts and put it together.. to those folks, they just want a "turn key" vehicle.. their enjoyment comes from just driving it, not building it.
That truck dosen't look bad, and apparently runs well, but based on the description, isn't restored, either.
I'd guess if the guy were to drop his opening bid to somewhere in the $6,000 range he might get a bite on it, but ten grand is pretty steep.
First off, it's HUGE which cuts the intrested buyer pool in half or more, since the buyer is going to need a place to park it.
Second, it's a COE.. I don't think there are nearly as many intrested buyers in the COE market as there are in the "conventional cab" market.
Third, alot of dudes who bag a COE for serious hauling put 350's in them, and mount the engine behind the cab.. don't know how well that would work with that monster box on it.
Fourth, how the heck would you get it? You'd need a monster flatbed to haul that thing home, unless you drove it.. either way, if the intrested buyer didn't live close, it would cost some bucks to get it home, i'll bet.
I guess it would be neat to use it to haul your classic car to the show.. but not nearly as neat or fun to DRIVE your classic car to the show.
In short, to sell it even at the $6,000 mark, you're going to have to find a very specialised buyer for that sort of vehicle that has the bucks to have it transported, or lives close by.
The more I think about it, $2500 is probably a more reasonable starting price.