As inlineskater says, there is no meaningful comparison between any two RVs & RV owners insurance costs. Or the "right amount" of coverage for for their needs either. You need to get quotes from several companies, or use an independent agency that will shop for you. Millers RV Insurance is one such.
I currently use Allied (A Nationwide subsidiary) through the FMCA group insurance arrangement. In the past I have used National Interstate and AARP/Hartford. Others like Progressive or Good Sam (National Interstate) or Blue Sky, but those have always come up more expensive for me. They may be spot of for you, though, so get a quote.
First, however, you need to think about the amount of liability coverage, collision & comp and their deductibles, whether you want Replacement Cost or Actual Cash Value on the loss coverage, and the amount of personal property coverage you need. Don't rely on the agents guesswork, or at least question him on those items once you get the quote. It's not a one-size-fits-all.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL