I don't have the time to do it, but have noticed that some CGs essentially have 'unadvertised' rates that you find out about when you camp there-usually for longer stays-and yes, places within walking distance to the intercoastal or Gulf.
Also-monthly, seasonal, and cash deals can be had if you search. Everything is relative, so what I consider a good deal may not be what someone else does.
Friends have sublet a site from others(site owners) in gorgeous properties that are ownership based-for much less than if they rented weekly/monthly from the properties management company. Also-there are some gorgeous mobile home parks that will rent spots to camp on in FL.
Shopping around and persistence will uncover some deals...