Yeah look at monthly rates for RV parks in the area you are interested in. Expect sticker shock south of I-4. Rates will skyrocket during the 'season' which runs from Thanksgiving to late spring every year. Florida is packed with RV Sales lots. You can pick up a good deal in a used Travel Trailer especially if you don't not plan to move it once you get it placed.
But I strongly suggest looking at RV Bathroom facilities, they may not meet your definition of a "good bathroom"
And lastly Craigslist for the area you are interested in will probably have very good deals mixed with over priced units by folks with a poor grasp of the market.