PaulS
Touchdown! Greaser!
Lots of talk and conjecture, but no real data about what's wrong with the engine. If I were OP, I'd want to see a report or estimate that leads to the conclusion that the engine needs cam and lifter work. I'm not doubting that it needs work, but without knowing what kind of work, we don't know if the engine is capable of an IRAN, or needs overhaul.
I think the issue is you are really not going to know the extent of the issues until you open the engine up. No seller in their right mind would allow that from a potential buyer. My take on this is that the seller knows he will not make as much money if he fixes it as he could make by getting someone to over pay while it needs repair.