For what it is worth I talked to the General Manager at RVs for Less today and was told that:
- the cost is $300 if the frame has not already been built and $1500 to add it after the fact.
- The riser is strictly to achieve a level towing condition and is most needed for Dodge trucks, as their beds are the highest made and thus are most likely to pull un-level.
- GMs without the riser will see a slight off-level that is all but undetectable to unknowing observers and I am thinking my wife's wardrobe in the bedroom closet will really bring it very close to level
- Fords are the least likely to need it as their beds are much lower than the dodges.