do you have insurance on the bike? if so, you might want to call them and tell them what happened. if it was the other driver's fault, they might go after them for you and get their insurance to pay.
other than that, i think you would need a lot of pictures of the bike to show what it is and it's condition. next you would need proof that people are buying/selling these and the prices they sell for. that would be your value. check nada and see if they have valuations for your bike. any completed ebay auctions for a similar bike or local ads selling a similar bike might be helpful too.