Well, sky is the limit when it comes to spending money.. for the more affluent of course! The costliest car (street-legal) in production today that one may go and but off the shelf is the Bugatti Veyron which costs a cool Approx. $1,700,000 (last update: 1/19/2007) and then there is the 10001 bhp that comes with it. The top speed on this beauty is 253 miles/hour which is approx 407 km/hour! Whew!
The car is built by Volkswagen AG subsidiary Bugatti Automobiles SAS in its Molsheim (Alsace, France) factory and is sold under the Italian/French Bugatti marque. It is named after French racing driver Pierre Veyron, who won the 24 hours of Le Mans in 1939 while racing for the original Bugatti firm. There are more expensive cars in Dubai... the Sheikh supposedly has a Bentley studded with diamonds and all! But it's souped up! Modified so not original.