Found a 1968 GTX 4 speed 440....Value?

I think in 68 they started putting the VINs on the blocks.
Honestly IMO only going with your description I'd call that a little strong. If you goal is to make money, you'll need to get it way less, assuming you have some repairs to do while you drive it. The market is crazy, but not because it's strong - because it could go anywhere price wise.