You can use
Rvparkreviews.com to get user reviews and prices paid for many RV parks and campgrounds. But take some of the reviews with a grain of salt.
And although resort implies something upper level and therefore high priced, the term resort can be used by anyone wanting to make their place sound high end. We have often stayed at an RV park in southern Colorado with resort in their name. They do have lots of amenities, but is not what I would consider within the meaning of resort. And although their standard RV sites are in the $30+ range, they have a long term area (month or more) for under $20/night. But they are only open late May to mid Sept. .