Teardrops n Tiny Travel Trailers

I have been thinking about buying a used motorhome that I could use to pull my 7x16 trailer and wondered if anyone has any experience with these? what kind of gas miles they get pulling a trailer? I have read 8-10 which is what I am getting with my suburban?
I have found a nice 2003 C class motorhome with 18,000 miles on it and they are asking 28.000 I really don't want to spend that much and they may take less,but older ones with more miles are in the 15-20.000 range.
I guess the fewer miles they have on them the more they can get for them.
I don't think I want a A class but they are selling them pretty cheap these days when I look on Ebay.?
I think I should rent one before I do anything so I guess I should start there,anyone rented one?
I may never buy one but I keep looking at them on Ebay and craigs list<>I am kind of afraid to go and look at this one because it looks really nice>?

I have a 2010 Class C that is Four Winds Chateau 28A, almost 30' long. It tows 5000 lbs. I sometimes tow my daughters Avalon on a dolly, so my 5x8 CT is no trouble. My mileage is 7.5 to 8.5 on a good day without a trailer, 7 to 8 with the dolly. I doubt the trailer makes it much worse because the biggest issue with a motorhome is the fact that you are sending a billboard down the road at 65 mph.

Renting one is a great idea. You don't really know what you prefer in them until you try them out. I am on my second motorhome and picked the right one this time.

LOTS of motorhomes pull cargo trailers with cars in them. Just make sure you are not over the rating on the motorhome._