Yeah I suppose, but its more safer to know what your getting and you can acctually hold and see the item your buying, unlike online shopping. There are hackers out there I tells ya, HACKERS!
Oh yeah platinum also depends on how much it has sold, how good, how long its been out. And I'm not surprised KotOR1 is a Platinum game, I got my KotOR1 on PC Months ago! and it was an EA Classics, so I got it for very cheap, about $20 (AU) I've been lucky Ive got good games at dirt cheap prices, and not crummy games either.