My floor is all fiberglass. I imagine yours is also. As far as I know, no wood was used in the floors (specifically the stringers) since the mid 80s. If you have some flex in your floor one of the removable centre panels may have a crack and may just need some reglassing underneath.
You were asking about carpet cost....
I've just ordered 18 feet of the 8.5 foot wide Daystar Lancer 20 oz. carpet from Overtons. They sent me a sample card with all the colors on it and the Light Grey was an exact match to my current carpet. I sketched out all my pieces to scale on graph paper to make sure I ordered the correct amount.
Is your boat an open bow? If so, do you have the square center floor piece that sits right in the walkthrough area? As you can see in my post above I'm stumped as to how to get this piece out. Judging from the photos above mastercrafttristar 190 was able to somehow replace his carpet there.
2005 X2, Viper Red, MCX, OJ TZ-X5 prop, PPass, rear 750 sacs, KGB, IBS, Bennett Wake Plate, custom wake shaper
(previous) 2001 X5, 1991 TriStar 190