If you have a 300 dollar stereo, you probably don\'t have digital inputs.
If your stereo is an "all in one" kind, it will probably only have 1-2 inputs, but that\'s enough. Just take the three color cable from the PS2, yellow goes to tv, and red/white go to left and right inputs on your stereo. These often can be put into the "phono" input, or "md" inputs. You may need to get extension cables if you don\'t have some lying around.
If you have a seperate component stereo, it should be even easier, most amps have multiple inputs video/sound, and then take the output to your tv.
I would really recommend you save up and buy yourself a seperate component stereo. I saved for about 5 months in 1999 (including 1 birthday, and christmas), and bought myself and amp, a cd player, and 4 good speakers. The amp alone was 1700 (CDN), but boy, hooking up the PS2 with an optical digital cable, and using Dolby Digital/DTS really improves the games you play and (especially) the DVDs you watch.