On RV's, "MSRP" has little to nothing to do with manufacturers. Those advertised MSRP's are set by the individual dealers (pronounced stealers). The prices are based on actual dealer cost, shipping costs, and individual dealer mark up. Some dealers, may have lower cost from the manufacturer, due to high volume sales, some have higher overhead costs, and some just have a higher level of greed.
That is why you can see two RV's, the same (make/model/options) in every way, at two different dealers, even in the same city, with two different MSRP's.