Its the Reventón Roadster
Actually now it is the Aventador J. The J is a one off, roofless, windshieldless, Aventador that requires a Helmet like a fighter pilot to drive, and was bought for 2.8 Million dollars. Check it out on Google Images. It's really really really cool. For those who don't know "One off" means they're is only one made and will only be one made. The Owner has asked to remain anonymous.
Lamborghini. company..
If you are asking only about these two cars, then the Lamborghini is the more expensive, and better performing.
the lamborghini gallardo superlegga.the superlegga is about 300 speed
Buggati is the most expensive LEGAL car. So Buggati is more expensive.
$1.5 million
The most expensive Lamborghini car that was sold were the Lamborghini Reventon and Reventon Roadster. Only 20 Reventons made. Lamborghini says that they will be making a track-only car called the Sesto Elemento. Only 20 will be made. They will be priced from 2.6M-2.9M.(!)
The most expensive car in the United States is the Lamborghini Veneno Roadster.
Lamborghini's bike maybe or Yamaha or Kawasaki
Rolls-Royce, Mercedes-Benz, Lamborghini, Bugatti....
There are many cars that are considered to be expensive, but the most expensive cars include and are in the order of most expensive to least expensive, Lamborghini Veneno, Lykan Hypersport, and third the Veyron Super Sport.
The Lamborghini Veneno Roadster remains the most expensive car of 2014 with a price tag of $4.5 million dollars.
There are a number of very expensive convertible cars. The top 5 most expensive convertibles are the Rolls-Royce Phantom Drophead Coupe, Lamborghini Aventador, McLaren MP4-12C, Ferari 458 Spider and the Lamborghini Gallardo. These are all 2013 models.