The rumor that PS3 games are going to cost $75 to $84 was pretty much inaccurate, and caused by a simple conversion from yen to dollars instead of any official price release. The official price in the US, as listed on Sony's official Sony Style site is $59. Same as the Xbox 360.
Though, it's a bit strange that Japan will be paying that much more than the US for PS3 games. Seeing as Europe's Xbox 360 games are nearly $100 USD now, $74 to $85 would be a bargain for them.
Sony Style [Sony - Thanks Weatherman!]