There is no quick and easy way to choose and buy a motorhome the best suits your needs, tastes and desires. Most major brands have levels of quality/features/cost and multiple floor plans. If you are mostly alone with two dogs, you won't "need" a 32 footer with slides, etc. A motorhome is a van with a house-box full of appliances and an AC/DC electrical system with a charger/converter and batteries that must be maintained to control and power the air conditioner, appliances and devices that give most of the comforts of a small apartment. If you buy a new "rig", you may not have many things to fix under the warranty. With a used rig, you may have things to fix/have fixed/replaced before you can safely travel and fully enjoy all of the features. Tires may need replacement due to sidewall cracking from just sitting parked long before they are 7 years old by date codes imprinted on them. Figure on tire replacement after 5 years regardless of tread depth/appearance. Appliances and air conditioning units may need major repairs or replacement after some 10 years. Roofs need periodic inspection and re-sealing to prevent expensive to repair dry rot water leak damage. The Ford E-450 engine, cooling system, and drive train are pretty much trouble free for 100K+ miles with normal maintenance. Take your time and get familiar with brands, features and floor plans and choose the best compromise. Many RV'ers own a succession of two or 3 different rigs as their needs change. Try not to buy an older "money pit"
and investing in cost of repairs that exceeds market value.
