This is hard for a relative newcomer to do, but in addition to the cosmetics, and making sure the stuff that is installed works, the systems need to be clearly understood in the context of how you will use the coach.

In English, make certain you have an overview of the systems and they are right for how you use the coach. On another thread there is a discussion about trying to run a house air conditioning unit from the inverters. The reason is the bus is set up so only one will run and the owner is going to rely on driver's air and that air conditioner for comfort while driving.

Anybody that has a coach set up like that and is trying to sell it will tell you how good that system works. Don't believe stuff like that. Prove it for yourself. On a hot day, drive into the sun and see how it works. If you are comfortable, that's great. If you cannot get comfortable walk away because those are expensive issues to correct.

Or how many inverters does the bus have, and what happens if one fails? I know of several coaches by several converters, mine included that will not by-pass electric if the inverter fails. What does that mean? Well if the inverter fails and the refrigerator full of lobster tails and steaks is on that circuit, even if you connect to shore power or the generator is running you still cannot get power to your now defrosting refrigerator. This is not a big deal if the inverters are easily accessed, or if the converter created a way to by-pass the inverters. but if not the bus has a system design flaw that can create serious problems for you when (not if) the inverter pukes. Failures of key components never ever occur in the garage at the end of the trip when you have time to fix them. They occur when you are at a rally or on a trip and need to have solutions for temporary repair.

Does the bus you are looking at have a back-up water pump? If it has two pumps a single pump failure means you may not be able to flush and shower at the same time, but you will have water. A single pump with no back-up means when it fails you are sharing the toilet with thousands of your closest friends at rest areas.

What kind of air conditioning units do you have? Roof air or Cruise Airs? Do a search for posts about the good and the bad with them.

How about long range fuel tanks. If you are going to drive longer distances nothers spells economical fuel purchases like having another 90 gallons on board. You can tanker fuel and shop for good prices. Having standard tanks cuts down on your flexibility.