Deck not floor, so we are all using the same terms
Dont be surprised if below decks isnt pretty.
Trading 1 used boat w problems for another used boat thats likely to have problems too, is an easy way to spend lots of money, unwisely.
If you spend $2500-3000 fixing this boat. You'll end up w a boat in significantly better shape then 99% of the used boats for sale at $3-4000.
Maybe you can find a used boat that falls into that rare 1%, most dont. They buy a 2nd boat that ends up costing about the same to repair correctly as the 1st would have.
Read some of the other topics in the resto forum before you cut into the deck. You'll see lots of examples of what you're likely to find. Many that start as relatively small soft spots in the deck end up as full gut and rehab.
Good luck