I checked out something called the Blue Dolphin ferry from this website http://www.tsugarukaikyo.co.jp/global/english/, but it seems damn expensive! A round trip ticket for a car and two passengers in the cheapest accommodations (shared area) runs $400 bucks. This relates to the roadtrip I mentioned over here http://www.fuckedgaijin.com/forums/viewtopic.php?f=10&t=30112 which means I am trying to roadtrip across Japan on the cheap. It looks like a train ticket from Aomori to Sopporo is only $50, but then I'd have to rent a car in Hokkaido, which is about 1.5x more expensive than from Honshu.
Any suggestions??