Wood you buy a house with known black mold?

How much in seller concessions would you ask for?

We were thinking before we got deep into inspections that we would probably end up asking for like $5k in concessions for minor issues, until we started looking behind a few known water leaks and found a bunch of black mold. Now we are thinking of either asking for a ton in concessions or maybe just not doing the house at all.
modnegged4life