There's deals to be had anywhere that a problem looks or is big, for sure. But I'm wondering what kinds of problems a home might have that are harder to deal with than a failing foundation. I guess major mold issues? Someone else discovering and claiming mineral rights under your dwelling?

A foundation issue might seem totally beyond reach for someone who has never owned a home before, but it's still a lot less painful than living in a bad location. Once you spend some time learning how the foundation systems work, it gets a lot less scary. There is a solution for everything.

Pier and beam foundation issues are essentially a non-event in my view. If you can literally crawl underneath your house and touch everything, it's basically like cheating.

With slab-on-grade things get more challenging, but installing piers on the perimeter and fixing internal slabs is not really a crisis situation. Concrete work has a huge advantage at repair time in that it can be polyjacked. This is easily the least intrusive form of concrete repair that is available. You can raise a slab of arbitrary weight in 15 minutes with a half inch hole. This repair technique will last ~indefinitely if you also have a tough talk with your landscapers about getting water away from the house.

Foundation has a limit - the cost to raise the house as if moving, removing the whole foundation, and building a new one.

Other structural issues can be much worse (mold is one, but think cross beams that miss the load beam).