Sure, of course its completely different. It's pretty much impossible to sell a legal hackintosh with the OS already preinstalled. If you really want to be completely legal you can just not install the OS (only include the retail Leopard install cd), and strongly indicate on the auction that it is theoritically possible to install the included OS on the machine. You can provide all the instructions on how to theoritically install it and theoritically you wouldn't be breaking the law. But, of course, a hackintosh auction would be more appealing if everything was already preinstalled and preconfigured but that comes with a legality risk.