Although there is no federal mandated MSRP sticker required for RV's, Section 5 of the FTCA requires that if sales material specify a specific item, that item must be true. So, under Section 5, if they use a Manufactures Suggested Retail Price, the manufacture must have actually suggested that retail price. The dealer can't make up any MSRP unless the actual manufacture made that suggestion. I have sued this before to force a no profit sale under threat of a lawsuit.
So, you have to look and see if the M in MSRP actually says "Manufacture" or if it says Market. Additionally, manufactures of non motorized RV's can provide a suggested retail range which means two identical travel trailers could have two different MSRP's so long as they are within the actual range.
And let us not forget that some States have stricter consumer protection laws concerning advertisements and sales materiel.
As mentioned, RV dealers are as bad as the buy-her-pay-here used care salespeople, but I fault the consumers who spend more time researching porch lens color over the sales protection process.