I just recently bought a new van from Wag'n Tails and they made it pretty easy. Dennis said financing is easier to get for a new vehicle than for a used vehicle. Wag'n Tails got all the financing done for me and Mercedes gave me the best terms and financing options for the vehicle I wanted. He also told me that had I chosen to go with a Ford or Dodge van, financing would have been faster, easier, and much lower down payment. When I approached both of my banks, Chase and BoA, neither one offers commercial vehicle loans for small businesses. I have excellent credit and the required down payment, so I'm sure that helped get what I wanted.
Personally, for me, I did NOT want the headaches of maintenance issues from a used vehicle like what might be available at the price range you mentioned. You might be able to get owner financing if someone was desperate enough to get rid of their vehicle, I don't think it would be rude to ask. But I really would be wary of a used grooming van that someone would let you make payments on. I shudder to think of the hidden problems you might encounter, which would then leave you unhappy, in a contract, with van payments, and potentially vehicle problems you can't afford - leaving your van sitting parked in your driveway. It's not something I would do.
I second what cockerlvr recommends. Save up to buy a van, new or used, and RESEARCH, RESEARCH, RESEARCH what you do and don't want in a van, why certain equipment might work better for you and why (i.e., diesel engine v. gasoline, generator v. battery bank, inverter system, etc.). I read and researched for over a year before buying. And obviously, improve your personal credit. That, and money to put down are the most important factors for getting financed.
Finally, you might want to consider buying a trailer to get started in mobile. There are some very nice NEW ones available in the $20k range. I would be more confident buying one of those than a used grooming van with lots of miles and a used generator, but that's just me.
Good info, I am considering whether to go with new or used too. Nice to hear one side for going new. I am not the best judge of buying used, will definitely need a mechanical oriented friend to help decide on a used vehicle if I go that route.