Unless you don’t mind spannering or have deep pockets a 40yr old car might prove to be a bit of a pain. They were galvanised but it was a long time ago. They’re pretty resilient things but can hide a world of pain.
I gave my mate a 944s ,his repair bills for getting some of the panel work derotted has been eye watering I think 1-2x your 5k.
That was after the plastic timing chain guide had managed to disintegrate causing a minor bit of engine self destruction, even spannering that himself there was a lot of issues getting someone to weld a piece of the head which was broken off of the used replacement he’d sourced which wasn’t in the greatest condition before the delivery company dropped it.