Not a bad deal. Chasing down all those extra parts would drive you crazy. You'd still need a few things, not sure if he's including heater & vacuum pipes, brackets, sensors, nuts & bolts and the little stuff. Don't forget freight, air intake, intercooler, belt, hoses, relays, boost solenoid, downpipe, exhaust, etc. It is a conversion not a replacement.
Labor to install, set-up, re-wire the new wiring harness is going to be fun unless you're a skilled wrench. $2800 is just the begining. You have a safe place to do all this? Be sure what you wish for.