You are trying to compare two entirely different animals. IMO, you would be well served to slow down and first think about what you need/want in terms of floor plan/space, how you will use it (short weekend trips vs. longer trips over mountains, etc.), what you intend to tow with it (will you want to tow a car along?), what kind of stuff do you want to take with you, etc.
Once you develop your list of criteria, start looking for a coach that best meets that criteria within your budget. The most important thing in any used coach is how it has been maintained. There are a lot of choices in both the gas and diesel family.
