See this link for the difference between a Class A - Motorhomes and a Class B - Van Campers.
http://www.carolinacoach.com/rv_classes_explained.asp
I dont know how to clearly explain the difference between a RV and a Camper - a type of RV but generally is not a Motorhome. You definitely cannot get a Motorhome style RV (Class A) with only Tens of Thousand.
A basic RV has kitchen, living area, sleeping quarter, bathroom, shower space. RV is a Motorhome.