Last year just before the 360 launch I posted the specs for both in the tech zone don't know if its still there but at that time the PS3 was NOT going to have a built in HD and it would still rely on the memory card as it does with the ps2 now if Its changed since my bad....
EDIT: Just read that it will have a HD and here are the prices for the different sizes....
Sony is now planning to give the PlayStation 3 a simultaneous worldwide launch. The new system will be available with two different hard-drive options in Japan, the United States, Europe, and Australia in November. The console will hit Japan first on November 11. The 20GB model will sell for 59,800 yen, but Sony will let Japanese retailers name their own price for the 60GB version. The PlayStation 3 will launch in the United States, Europe, and Australia on November 17. The 20GB version will retail for $499 and the 60GB version will retail for $599 in the US, and 499 and 599 euros in Europe, respectively.