Unfortunately the classic Japanese bikes are rising in price. Hard to beat any of the Honda CB, CL 350 or 360s, and of course the Yamaha XS650, the best Bonneville Triumph never made, Yokohama Bonneville.
Those old Hondas and Yamahas just have a lot of class to them, and from what I have heard, they can take a beating. I have been keeping an eye on a few Honda CMs and such from the 70s. I think if I stay in the "new biker" range of 200-250cc (I like small underpowered vehicles anyway), I ought to be able to keep my budget, not to mention how much cheaper insurance is. However, we will see how I feel after I learn to ride the darn things in the Spring.