someone gave me a Mac Mini G4 over the weekend with Tiger on it. My first Mac. i set it up and went on ebay looking for 10.5. all the auctions end over $100, with a lot around the $150 mark. is there any reason why the last version of the OS is so expensive? i also see a lot of people selling the OEM OS discs. will the OEM discs from an Intel Mac work on my G4? i assume they will.