With a $40,000 budget and a fixed retirement income I think you will do better with a used Class A and a small tow car if I understand your OP correctly. If you were to stay in one place for any length of time the 5th wheel might have an advantage, how ever if you want to travel and site see the A tow car combination will give you much better overall fuel mileage. I usually put as many miles if not more on my tow car that gets 40 mpgs as I do on the MH so I average 23 mpg for the combo. Also if you plan to winter down south in one area after you both retire it would be cheaper to buy fuel for a small car rather than a truck. You will be buying used so to me having two vehicles to drive to a parts store in case one breaks down is a plus. I spent $40k on this combo 10 years ago and had to use both vehicles for repair over the last 80k miles of travel. The 5th wheel will have more room to camp in, but the A is more comfortable to travel in easier to set up camp.
