I´m interested in this 1972 BMW bike someone I know is selling..they don´t have a good idea of what it´s worth these days and I really don´t know what to offer...I don´t want to leave the seller feeling unsatisfied but at the same time they´d like me to have it for a good price. It´s in "good" condition not "excellent" it´s had some repairs and has been sitting for a few years. It had been driven once in the summer of 2003 and reportedly worked fine. It runs now. What is this bike going for these days? answer if it´s not too vague...in US dollars (i´m in Canada but I´ll do the conversion)...thanks in advanvce if you can help.