Ditto on trying them out first.
That is what I do as a traveling Full timer and want to set down levelers for a month. I sign up for a day or so at a CG BEFORE I decide to stay for a month.
Unlike the midwest where we have what is called seasonal sites which are costly and usually require a contract, Florida does not have seasonal sites per sea. Cause they're open all year round. :W
Central Florida and North Central Florida have very reasonable nice CG's that offer monthly, 6 month and yearly stay rates. Actually the longer you sign up for the rates are lower.
If you want to stay on the coast lines and/or in popular tourist areas yes it will be very costly.
Also keep in mind that in Florida it is usually CG policy to quote you a rate that does NOT include electric. you need to know what that will add to your rate, as it is billed separate. Good Luck!