What do you already have for your playback system? If you're starting from scratch with a $500 budget I'd suggest that you look into buying a source, headphones and a headphone amp and then add speakers, preamp and later when you've got a little more to spend. For around $300 - $350 you should be able to get a cheap source (Toshiba 3900 would be great), nice headphones (AKG, Sennheiser, Grado, etc) and a headphone amp. IMHO you'll get way more bang for your buck this way.