well that is a pretty tight budget for a new cd player, a sub, and an amp. With that being said you can get yourself a nice system for that price.
Pioneer, JVC, Kenwood, possibly entry level alpine is best bet for CD players.
Sub: Stryke Audio 10 or 12 ($140 for 12"), Lambda LE 10 or 12 (use to be $79 for 10, 84 for 12...however they may have gone up)
Amp: JBL 600.1 (~200 from ikesound)
Build your own enclosure.
or else you could get one of the infinity basslinks for like $250 that has a 10" sub and a 100 watt amp built in.
Wiring from knuconeptz.com (hes a contour.org member and has good wiring)