re: Why are class B RVs so expensive? Compared to A and C class?

Those vans are the worst deal in camping, IMHO. Even if you are only using the rig 2-3 times a year. If the trips are long, you would be much happier in a short Class "A" (30-38') and the newer models with piston steering assist and modern suspension handle MUCH better than the class A's of the past. Also, don't pay too much attention to the list price you see on the new units... Most dealers I have negotiated with will give a giant price cut with an inquiry email. Those 150k class A's will be 120-135 after you mention that you are in the market and more once they find out you are serious.

Having a full sized refrigerator that runs on propane, a full sized shower that you can stand up in and a king sized bed to make Ponce on Mrs. Napoleon will have you questioning why you ever looked at van. Throw a motor scooter on a rack on the back hitch for less 1K to make emergency beer runs or using uber to go to dinner during your trip makes up for what you give up in mobility.