Snow bird RV parks ?

You didn't say what part of the country you planned to occupy. We stayed last year in Silver Springs, FL and paid $400 a month + electric/cable. There was a place just east of the that was farther from the city, nicer facilities that was $550 + utilities. We have friends that stayed in Key Largo and paid $4,200 a month for the winter so they could be right on the Gulf. It just all depends on what you want, the amenities you require, what hobbies you have, and how much you want to spend.

I will say that in high value locations, if you don't reserve early you will not have a space. YMMV