There's a reason for that. U.S. accounting law requires that non-subscription devices that are upgraded have a fee associated with the upgrade under Apple and m

There's a reason for that. U.S. accounting law requires that non-subscription devices that are upgraded have a fee associated with the upgrade under Apple and many analysts’ interpretation of the law. This is why iPod Touch owners have to pay for upgrades while iPhone users do not. I think Apple may have relaxed that recently though, and I wouldn't be surprised if they release Mountain Lion for free.