You mentioned the survey. Yes, FL has annual registration fees, approx $100 depending on length of boat. Insurance has always been required where I've been, but may not be everywhere. Delivery charges to get the boat home. Maintenance is almost always deferred to some level on a boat being sold, bottom paint
, etc. Marina charges, slip or mooring. Then I've always had the experience of fixing tons of stuff that shows up the first season. After I get all caught up, it seems to settle down.