3 adult size people, spending alot of time in the RV, I think a medium sized C is about the smallest I'd consider. Not that unwieldy for a 26-28' vehicle. Think of it this way, it's about 6' longer than a long bed crew cab pickup!
Best resale, IMO is the one you get the best deal on first, lowest miles (so the miles are still lower when you sell) and old enough that the annual depreciation is not a factor (IE over 5 years old).
Budget wise, you're wide open at $60k max, but don't need to spend near that much for very full featured newer rig. $60k is approaching brand new, which is the WORST for resale.