A valuable car made even more valuable by its famous first owner.
There are some cars which become valuable because of a famous previous owner. There are some which are valuable because they have some kind of historical significance. Then there are some which have always been valuable, and now their high original price, age and rarity have added to its worth. Rarely do all of these factors converge into a single car, but one such car is this purple 1914 Rolls-Royce Ghost, first owned by Tsar Nicholas II of Russia.
The Ghost was owned by the Tsar for only a brief period, as he was deposed (and subsequently killed) in the 1917 revolution. It made its way into the collection belonging to John Ringling (of Ringling Brothers Circus), and is now sitting in a "nuclear bomb-proof bunker" in the basement of a mansion in Germany (note the irony). If you want it, the car is currently up for sale for about $7 million (€5.5 million).