I'll venture a bit of an opinion, having owned one similar to what you seem to be asking about.
You said "all beds in back". Well then you are perhaps looking for a B+ category instead of a Class C. B+ units often have an entertainment unit across the top of the front, and not a bed. They enjoy a better upper view from inside the cab while driving. Great for mountain viewing. Not as good because while sitting, often windshield drips come off the front from the roof.
With a unit like that, gas engines are almost used in every one except Sprinter models. Often it is a Ford E450 frame. That in itself is something you need to know about. Frames all have maximum weights, and an E450 uses up a lot of it's carrying weight when it gets 28+ feet long. After that, you have to go to a larger frame and a much heavier overall frame. Looking at Super C units? Not many available at all, and even fewer under your $80,000 price.
In a Class C unit you generally get the living area in the middle of the unit, and do not usually get views out the front windshield, or the rear. If it is to be just enjoyed by the two of you, they are not as common, and often harder to sell because of the lack of beds.
There really is so much to learn and to consider. Spend the time to really check out many options, rent and try (it is money well spent), and check out the differences between brands to know quality before you go look.
Mike
2012 Winnebago Impulse Silver 26QP
2005 16.6 Double Eagle
2018 Jeep Wrangler JK
previously Snowbird Campers,
Triple E Motorhome and Fifth Wheel