I guess all that moisture/rain does a doozy huh?

Here in PA, the disclosure form specifically states ‘do you leave knowledge of...’With that wording, it’s hard to say you (she) doesn’t have knowledge of moisture/water problems.

Splurge on a $500 model with a stronger exhaust and vent it all the way to the outside of the house, to avoid future repairs caused by excess moisture and mold.Worth it?

@Bryan Devitt The attic is sort-of finished and home inspector thinks there is no good air circulation and moisture which causes mold to form.

So we had both slab and pier and beam in soil with high clay content and pretty extreme seasonal moisture and heat variation.

I've got buckled and damaged hardwoods from the moisture in the basement, 8 of the windows are as old as Methuselah,  and worst yet, the 2 car garage has what appears to be the beginnings of a sinkhole on one side. 

It is legal in my state so I did not stop it immediately and the moisture damaged the ceiling.

Depends on your soil type and moisture. 

You should use a moisture tester on all the lumber and make sure it is dry before drywalling. 

The parameters for the inspection are pretty bare-minimum for any reasonably built and maintained unit,    but if you are looking at converting a basement with low ceilings,  uneven or dirt floors,  moisture issues, no or very small windows,  etc.