how come it says less then what it is worht i dont understand how this would work?

First it is always good to read the "Terms of Us" which has a button at the bottom of this very page. Second, Cargurus does not sell, buy, trade, ship, finance, repair, warranty or wash cars. Cars for sale are advertised here by individuals and dealers. Any deal you make has NOTHING to do with CarGurus.

Cars are often sold for less than book value. There are many reasons why this is being sold at that kind of a discount. It could be a salvage car, where it was crashed and rebuilt. In such case I would get it looked at by a reputable mechanic , before you hand over your hard earned cash. Bring it to your local Mini Dealer and let them go over the car.

Private sales usually are less than dealer sales. Owners price their car by what they judge the value to be. Sometimes you can get a good deal but if you want to pay more I am sure they will take your money.