Tiers of Motohomes

I wasn't saying Tires and mis-spelled it. I purposefully said "Tiers." The reason manufacturers have the same floorplans but different model names (Bounder vs. Southwind for instance) is because one is built with cheaper quality items, resulting in lower price. I want to know where I can find out which RV lines are the cheaper vs. the top line products by manufacturer and year. As an example, I think of the 7 gas motorhome lines I mentioned for Fleetwood, the Bounder is the low quality and Southwind is top of the line for that manufacturer, but I don't know where all the others fall into the lineup. (I know the discovery is a Diesel Pusher, so I don't compare it to the others listed.)

Thanks,