(DO you mean 'anonymous'? I just don't want to mis-pronounce your name.)
Anyway, if your friend says they'd like to get the floor fixed, there's nothing wrong with having 2 or 3 or more contractors come out to estimate the repair. If you want to know more about the cause of the problem, and either aren't getting it from the contractor(s) or are not satisfied with their explanation, have an ASHI-approved Home Inspector come to the house. They'll charge you a couple of hunder $$$ for a whole house inspection but maybe you can negotiate a smaller fee for just the basement. $50-75 wouldn't be out of line for good advice. (Of course he's NOT doing any physical work but he is advising your friend on the cause and possible repairs.) A Home INspector can estimate the cost for repair too. Just tell him what you want removed, fixed, AND replaced. If he OFFERS to do the work, report him to ASHI! It's a violation and they can be thrown out of the Society.
This is what I'd do, and what I suggest your friend do. My best to ya and hope this helps.