I don't think it's going to be a huge deal. The bank will make sure the subs have been paid for the work already done. The new owner will have a copy the plans which he can use for obtaining bids.Your post likely identifies a major issue for the OP. Likely hard to even have contractors come out for quotes.
Huge risk equals potential reward, but the buyer of this home better know what they are getting into. As others have mentioned, if this was a easy deal, the home would have been gone in hours, especially in Florida.
These homes aren't easy to sell because buyers who like to build want to build their own home rather than finish someone else's home. Most people don't want to deal with this sort of thing.