I am very interested in buying a classic CB 550F. I like the stock OEM look. What are the best years to buy one? Are their years that I should avoid. Not going to cafe it. I see them on craigslist ranging from $2,500 to $6,000 for a nicely restored one. I would prefer to buy a $2,500 bike and go thru the process of restoring it. Any thoughts, comments?