Come on now Jay =)
You know some of the time the people selling these cars are people who did all the work themselves and didn’t properly account for how much the swap was going to cost in the end. It’s not inexpensive to do at all.
You have all these domestic swap kings coming into the torque-central v8rx7 forums talking about how they bought a shell and the engine, but didn’t account for all the other costs, and now are looking to dump their project.
then there are the other people who finish it and then try and sell for a profit
to be honest, if i had the time and the tools, i’d be building these cars just to sell anyways! you can build one of these pieces for 17kish ( minimum, stock, finidng good deals and used parts ) and sell them for over 20 easily!
the last group are diehard draggers who sell their cars when they find a mint GNX for sale or something else… or they then get a family 
:shrug: but what do i know!
just my .02