www.lemans.org 
LMP1 & 2,GT1 & 2 The biggest teams,the best drivers in the business,together with gentleman drivers who pay a couple of 100K to particypate. The big guns spend in the order of a 100 million for an attack at the winning spot.
I remember Jan lammers,when driving for Jaguar in the '88 WSC and LM,earned 240.000 dollars a month!
www.dailysportscar.com
I think the best site for ALL Sportscar related info.