Well, the price of either is a matter of what you already have :).If I have the immediate previous version of the software:Leopard-->Snow Leopard: $30.Vista Home Premium-->Win7 Home Premium: $120 (if you want Ultimate, then $220)If I have the second-previous version:Tiger-->Snow Leopard: $170 (bundled with a couple other items)XP-->Win7 Home Premium: $120 (Ultimate is $220)Even earlier version (ra