price: $3.5 million
History is expensive, and at $3.5 million your purchase would send you back 124 years ago to 1894 when this first production motorcycle appeared on the scene.
Heinrich and Wilhelm Hidebrand were steam-engine engineers before they teamed up with Alois Wolfmüller to produce their internal combustion Motorrad in Munich in 1894. This momentous event started sending the flesh-and-blood steeds out of fashion, reinventing themselves as emblem of the refined gentry, while the special breed of men simply moved on and transferred their affections to the two-wheeled metallic petrol-guzzling steeds that took over the roads.
If you manage to get your hands on this and want to literally have a go at history by testing how it handles on the road, better watch for a bit of fun fact: with neither clutch nor pedal, be prepared to run and jump with this ancient one. On the other hand, your family, financial adviser, or friends would probably just drag you and bike to safety like the madman you are for putting such a substantial investment at risk.