For $500 all you could do is hunt for a super price on a CD player, integrated amp, and then, to really pick up some gains for the money, build some 2 way kit speakers.
On the original thread, it didn't even specify how many sources, but my amp and speakers were $1,500 each new(Biro L/1's/Van Alstine Fet/Valve 350hc hybrid tube/ss amp), my preamp a little under a $1,000 (Van Alstine hybrid), my DAC $1,000, plus a Parasound transport for $200 on closeout. Breaks the bank a little, but I've loved it for 5 years now. My Fanfare tuner is nice too but not included, and I'm using some old runs of Kimber 4PR I've had laying around for years. The Fet/Valve's don't care what cable is on'em, they just plow right through it. I've got some jon risch DIY room treatments too, another $50.