Personally I would not even entertain making an offer on a home with this problem.
I have worked on to many homes with the same thing and the homes are aways damp, musty, or eventually have mold problems. The mold could be in places you can't see. The present owner may have done something to mask or hide a musty smell.
It would be a rare home owner selling a home that would tell you they had a problem.
Damp walls are an indication of a lack of venting.
Not having a problem for 8 years means nothing even if true.
My recommendation is look for another house.