I'd delete the part of extensive music collection believe that is illegal... i think it is toooo much. u might get more to sell it off in parts than as a system. if no one actually responds to u're add then reduce the price or sell it in parts, somehow if u can wait u always get more for parts.
I would say 600 is good. 550 might be better, but you may get 600. It is a 4800+ after all, and can always be overclocked to hang with the newer stuff.
Eh, its craigs list. I really dont think Id get in trouble lol. I already got an email about it, So I'll keep it at 600 for a few weeks. After 2 weeks I'll drop it 50.