I would disagree, with, pretty much the entire statement. First, your best buy is about a 3 to 4 year class C. Buying new and trading it in every 4 to 5 years is, in my opinion completely nuts. Thing will lose close to half its value in 5 years. (that's like a 30kplus loss every 5 years) Unless you pay cash you will still be way underwater in 5 years.
Buy the right one, a few years old, get what you want and drive it till the wheels fall off. Bought ours 11 years ago. It was 4 years old at the time have put 60K on it and is still going strong. Have no plans to replace anytime soon