ich kann Eure Antworten aber nicht ganz verstehen:
Wenn die Einreise über Vancouver geht (wie gedacht) und kein Zwischenstop in USA ist, braucht man doch kein ESTA. Die Einreise nach USA erfolgt dann mit dem Camper, also auf dem Landweg.
Und da fragt niemand nach einem Weiterflug-Ticket, denn die meisten Touristen reisen ja auch auf dem Landweg wieder nach Kanada aus.

Der kanadische Grenzbeamte am Flughafen in Vancouver kann dich aber abweisen wenn du kein Rückflug oder Weiterreise-Ticket hast. Wie gesagt, das liegt im ermessen des Beamten und kann eben in die Hose gehen, wenn man nichts vorweisen kann.

Übrigens One-Way-Tickets mit Condor oder Air Transat nach Vancouver sind meist viel günstiger als Hin- und Zurück. Daher der Vorschlag mit einer kurzen und billigen Busreise nach Seattle.

Hello travelers.

We are traveling around canada and the us for a number of years, we have a camper (a dodge pickup truck with cabover) stored in the vancouver area and we are not selling it.
But maybe we can help you with some information.

About the cars, yes the are cheaper in BC than in Alaska, but they are even cheaper across the border in the states.
But there are always problems with insurance , and ownership, and being foreign , specially after 9-11.
If you buy one in the states try the city's with a university (they do foreign people) and if you are young you pay a lot.
In the ninety's starting out from California we had to call 30 or 40 company's before we found on. ( farmestate in some states in the us is an option)
Try mailing the AAA maybe this time they know something. ( they did not 10 years ago ) after buying go to the DMV department of motor vehicles for registration.

There are some company's who will sell insurance from europe for the USA and other country's, i never used them so i do not know how good they are. http://www.alessie.com/ this is one in Holland usually very expensive.

What we found out is buying a pickup with cabover ( http://vancouver.nl.craigslist.ca
for secondhand) or a small van is the cheapest way to get around, is very easy in BC and insurance is also very easy just walk in any bc autoplan (acbc) insurance, you will find several of them in any mall in Vancouver and get state insurance (liability) that is third party only. ( you can get more but will pay for it)
Keep in mind that if you buy a car in the vancouver area you need a smogtest before reselling it (if you make it back) , if you go outside the greater area you dont.( vancouver island lots of rv )
Get from your insurance company in Germany a official letter with your discount or damage free years, you can use this trying to get a discount, this is not always working but worth a try.
The only thing you need is an address in BC ( the best is to make some friends, but if you cant find anybody just an hotel or something)

The insurance is roughly 100 can dollars a month, depending on your age and having no deduction.And you pay some extra fee for the plates and other stuff.
It is valid for 6 months and and you can travel trough the USA with it.
I am not sure but i think you can extend the insurance time once, but just e mail any autoplan insurance and they will tell you, and because it is a state insurance they are pretty easy about it.
From Mexico on i dont know.
Borders, canada no problems (6 months in out) whatsoever but the us is a pain in the but, first time crossing is no problem, you arrive in a car and after an iris scans and paying some money you are in for a couple of months but after leaving the states it is difficult to return the same year.
We did manage once after a lot of talking, but that was years ago.
Be prepared for some very unfriendly customs, the see themselves as the last line of defense and every one of them can stop you from crossing the border, visa or no visa.
Crossing the border to the states whit our own car they never asked us to show a return ticket.

For the tickets, years ago we went for a year, buying a ticket where you could change the flying dates once or twice, i think it was Britisch Airways, set the first date within your visa limits andn later in the BC change the date.
Once we had just a one way ticket and we had to show that we had enough money to go around.

Don't let anything keep you from traveling, in the end we always found a way sinds the 1980 ties , not always cheap but always a way.

Good luck

Tjeerd
Holland