Perhaps he priced it according to how much money he has invested in it. I have one like that, I used to keep up with my investment amount but it got too depressing. Now I look at it like this, What price would I put on my enjoyment of owning, working on and riding the old beast? Another way of looking it; If I paid $11,000 for a new bike, would it be worth more than I have invested in my old one at this point?
He "spent" money on it---he didn't "invest" money in it. Motorcycles are, generally, not investments.