Having recently bought and sold a boat in spain, there is no need for a local bank account. You can do an international transfer. For around $25k, our credit union charges $50.
The only catch with that is ensuring you get a clean title in your hands once the cash is transferred.
The bigger question is registering the RV. This is done at the state level and varies from state to state but most want an in state address to tie it to. I know there are ways around it but not having done it, I'm not sure exactly how.
Prices do vary by season but not by huge amounts and if you get the discount it's because it's not a good time to go camping in the area. If it were me, I would go looking in Arizona (Phoenix area). A lot of retirees spend the winter out there. A lot of them die or quit and then there is an RV to get rid of. They usually don't have the wear and tear kids put on the units and are generally better taken care of (no guarantees though).