[COLB]

If they get it running, driving, and stopping, the price is probably going to be over $15k -- even if it grinds going into second, leaks, and sputters.

If you can get in well under that, you are probably fine -- if it needs more than you want to put into it, then you can always resell it.

If the rust you are talking about is around the seam of the rear glass, that is a big warning sign of rot that goes much deeper. Check the rear seat pans. If it is the dark spot on the rear deck, that is less of a big deal.

Regardless, if you think the owners are going to go for a PPI, followed by a needle-dicking negotiation where you point out all the flaws, you are almost certainly fooling yourself.

This looks like a "pay your money & take your chances" deal. And if you are not willing to accept the risk on those terms, someone else certainly will be.

Forget about how much money it would take to "make it right." This is a car you drive as close to "as is" as you can.

If you want a "nice" and perfectly reliable car, you are looking at $30k. Better to buy one that is already in that condition than try to get a beater up to that standard.