[JC455]

Ummmm.... Ditch the motor and the 'custom' installed computer- after that, you have a shell to build off of. Also, you can keep the door panels.
IMO, all the parts that're listed as 'upgrades' in the ad are the cheapest, low-buck crap he could find. He could've gone full Global West, SpeedTech, SPC, SC&C, etc. and had an incredible suspension/brake package. Even at MSRP pricing, those systems would all have come in under $10K for the super-duper setup.
Interior? Everything needs to be replaced.
Drivetrain? Needs one
Paint and body? Needs a lot.
Wheels? I'm fine with the big rims, but they serve a purpose: to allow BIG rotors. This poor thing has Chinese versions of GM brakes. We've all had to use foreign-sourced parts, but this thing is dripping in them.
Trim, Chrome, Grilles, etc? Looks like everything has been scuffed and painted... Makes it look really cheap and shabby.

Honestly? I'd say it's a sub-$10K starting point for a decent performing/looking street car.