Jarang nmpk ko... 
it is same.. i personally suggest you buy from steam coz steam got lots of usefull fetures 

The new Prestige Pack introduces the beautifully realised, legendary Australian Bathurst circuit and 10 of the planet’s most desirable cars, including the Ferrari F430, Bugatti Veyron and Ferrari F550 Maranello. Gamers can also get behind the wheel of the Mercedes McLaren SLR 711, Lotus 2-Eleven, Lamborghini Gallardo GT, Mazda Furai, Jaguar XKR GT3, Honda Integra Type-R (DC5) and Lamborghini Gallardo LP560-4

The 8 Ball Pack delivers eight superb high performance new cars to drive in the game's 'Race Day' mode and online races. New featured cars include the McLaren F1 GTR, TVR Cerbera Speed 12, Mitsubishi Lancer Evolution X, Honda S2000, Nissan GT-R (S-G2008), VW Nardo, Pontiac Firebird Trans AM and the Volvo C30. The 8 Ball pack also comes complete with two new multiplayer events to compete in set on existing circuits from across Race Driver: GRID's three continents and designed to test drivers to their very limit online.