I haven't bought a Vanagon long distance or sight-unseen but I have
bought two other VWs this way.  It is definitely a leap of faith and the
car will always be less than you thought it was when you get there.
Just plan for it.  I have found sellers aren't going to lie when asked
things directly.  (EG:  Is there any rust on the bottom edge of the
door?)  They may squirm "I can't see any" or "Maybe a tiny little bit"
you just take that to mean "yes".  Don't go for any car that seems
'marginal' only go for the 'premium' and then understand that it won't
be 'premium' but will likely be 'very good'.  So ask a LOT of questions,
think about them overnight, and then ask a bunch again.  You should get
a lot of dialog with your seller.  Do some character judging:  if you
start to see character weaknesses in your seller know that you're a lot
more likely to be getting false information.  Get digital pictures sent
to you:  as many as you can.  Then, if you're still excited, go get your
car.  I would never buy sight-unseen.  You're better off having to bus
it home or something than to have a lemon delivered to your door.  Plan
then to put money into it.  Nobody sells a car once it has had all its
needs fixed.  Plan to replace brakes, CV Joints, Battery, belts, maybe
tires, etc..  The cooling system might need attention, the ignition
system  (wires, plugs, rotor & cap) will need some attention.  Probably
not all of those, but maybe all and definitely some.  Remember you're
buying a used car.  Your love for it has to be stronger than your desire
to get the best deal.
Just my experience.

Damian