Depending on how you plan on using your rig the most, CCC can be a huge consideration. I subscribe to the "more is better" school of thought. Our 24' E-350 comes with 3,368# of CCC and while we will never get close to the max it is nice to know that it is virtually impossible to overload it.
This opens the door to traveling with a full 40 gallon tank of fresh water, 55 gallons of fuel, bringing the spare (Honda), generator, firewood, all of the tools and toys I might ever need or want. Some C's particularly rigs with slide(s) sacrifice CCC for the additional floor space (which gets back to how you use it - which is more important?).
Not every CG has full hook ups and I've seen dump stations out of order or so backed up that waiting wasn't an option. The point being full grey and black tanks add a lot of weight which some C's with limited CCC simply cannot support.
I doubt you will find a Sprinter in your price range and while I am not a fan of buying a retired rental it might be a way for you to get the rig you want and stay within your budget. I would look for a slide less floor plan that you can live with that comes with lots of CCC and outside/bay storage. The Ford and Chevy chassis' are what you will likely end up with and that is not a bad thing. The sprinters are pricey and you will never save enough in fuel economy to pay the premium they come with.
As always.... Opinions and YMMV. Good luck! :C