Dealers costs ??
The RV manufacturer has high volume dealers (example; 15-20 a month) who can get a much lower price per unit than a dealer who sells maybe 4-5 units a year. Usually the dealer owner/mgr and his controller will be the only one at the dealer who will know what that cost is. Not even the sales manager may know that number.
Manufactures MSRP ??
or
Dealers invoice ??
Any price they want to use and will vary between dealers.
My wife was a controller for a large mobilehome/RV dealer for many years. She saw what the dealers actual cost was per unit on specific floorplans. The cost varied with the number of units the dealer took on in a certain period.
Words like MSRP or dealers invoice or manufacturers invoice all can be different numbers at different dealerships on the same brand trailer with the same floor plan and same standards and options.
This isn't the auto industry.