I know that snow leopard recently came out, and I really want to buy it. I heard that if you have leopard that it only cost $30 for the new OS but, I heard if you don't have it, how will best buy know the difference in you having leopard or not. I have leopard, but how will they know if I do or not, and which price to charge me? Or is this all wrong and the price is $30 regardless of what you have? Any help, Thanks people