Most places that I get older games from (Mac or otherwise) are local non-chain stores.

Furthermore, for something like Tony Hawk 2 (if that's the one you're referring to) that was released before the Intel Macs were known to the public. You would need a PowerPC Mac, or an Intel Mac with 10.4, 5 or 6 and Rosetta; possibly a virtual machine running 10.6 Server with Rosetta, although for some reason Parallels 10 and the 10.6 server image I had don't play nice (previous versions did...) Edit: Tony Hawk 2 might actually require PowerPC, since it's compatible with OS 8.6 and OS 9. Yay retro gaming!

Another note, most such stores will have an as-is policy for older games or PC games in general since they can't test every hardware configuration or verify that your machine is compatible.