You can get a 15" Ti PowerBook or a dual 1.25 GHz G4 system that dual boots with 9.2.2 from Apple, still. If you want a cheaper route, there is always the used and eBay market.
I have a G4 500 with 1GB RAM, a fat HD, uphraded video card and a 4X DVD burner I am selling soon. I think you are better off with a used Mac. My G4 runs OS 9.2 like a champ: the finder is super fast! OS X is wonderful, but it still lags like a bloated cow compared to OS 9's responsiveness.