Well, I got it for the PS3 and it was like $60 bucks at Fry's Electronics. XBOX 360 would be the same story I'm sure... and PC. PS2... maybe... $45-$50
When it's close to " nothing " I'd say less than 10%. In a survey taken by USA Today several years ago, the most popular answers for this very question was " about 3 % " and " very little ". 10 % is...