usually #3 piston(driver-side, rear) gives up the ghost, especially after the exhaust valve separates.
remove the generator belt, and try turning the engine over...BY HAND. if it turns, come back here, for a cheap fix.
whatever ya do, don't order that new engine yet! yours might be fixable.
FWIW, the fastest 2-man team could remove ANNNND reinstall the VW engine in 2-4 minutes...and drive away!
that was 20 years ago!