Approximate cost for floor framing indoor pool

Hi,

I have an offer pending on a house with an empty above grade indoor swimming pool. The house is built on rock, so they used foundation walls as the sides and poured concrete on the slope for the floor of the pool. This makes it more of an uncovered crawlspace right now than a pool. I would like put a floor over it. It's about 35' by 18', or a bit over 600 sq ft, with about 250 sq ft of pool deck around it.

I was thinking a contractor could pin 2 piers into the bottom to support a beam, joists hung from the walls and overlapping at the beam at the pool deck level, then plywood subfloor over eveything.

Materials should be less than $3k, but labour is a guess. I'm treating it like an unusual framing exercise and would put the work under $15k, perhaps even under $10k.

Any confirmation or correction would be a huge help.