Time to buy and how pay

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).

beware of any flood damaged units in TX, Fla, etc.
bumpy

Northern U.S. prices are seasonally similar to Germany. Florida different because the winter is a peak selling season while tourists are there for the season.

On new units, there are some reduced costs if you purchase near the factory and transportation is minimized.

Wire transfer from your bank to seller's bank is the safest method.

There is more of a location component in the market here than in Germany I believe.

Right now the prices in popular winter destinations like Yuma, AZ are likely to be higher than in the snow bound North Eastern US. However, there are many more units for sale in the winter destinations, so supply may be more than demand in some locations.

The point being, unless you are willing to travel 1000's of miles for some dollar savings, be happy with what you find in the area you are shopping in at the time you are trying to buy.

You will want to Google "How to open a US bank account if you are not a resident" or some similar search to see how difficult it can be. See if your present bank has a close affiliation with a US bank and/or will wire money directly to the sellers bank account.

Welcome to an adventure.
First question, yes prices here tend to be seasonal as well, price follows demand.
Secondly, on private purchases, about the best way is to meet with the seller at their banking institution, especially if there is still a lien on their unit and complete the transaction there with the title immediately available to you. Forged cashiers checks have become a problem and many prefer bank transfers when possible.
Happy motorin