The 1915 Cyclone Board Track Racer and 1907 Harley Davidson "Strap Tank Single" are both worth well over $700,000. The Strap Tank Single and Cyclone are both rare motorcycles that have less then 100 models available on the market.
One of the Cyclone Board Track Racer motorcycles was sold in May of 2015 at just over $850,000, according to Gizmag. The bike is one of only 12 produced, and was used by Steve McQueen.
The Strap Tank Single is the first Harley-Davidson Motorcycle built. There were only 100 model built and sold. Due to the rarity of these motorcycles, these bikes range from $800,000 to $1 million.