I think the source is important (the recording most of all)but that diffences between CD players is relatively minor compared with difference between speakers - That is diminishing returns start rather low with digital equipment IMHO, so I think a good $1,000 to $2,000 Cd player is going to be pretty darn good, wheras speakers differ a lot and you need to spend quite a bit more to really start hitting dimishing returns - maybe $10,000 or so. IMHO, the speaker choice must be made first and will determine the general sound of your system, the digital source while critical is unlikely to be a major weak link since to my ears at a certain point they sound more and more alike. After finding a speaker I like, I would spend a lot of time (not necessarily money) finding an amp that really works well with my speaker (great speakers, and great amps can sound bad if this interface is not well matched), and I would learn somethin about speaker placement and treating room acoustics.
Most Important?
After speakers where do you focus the lion share of your funds. I known garbage in garbage out. Would you buy a really great amp and an ok cd player of vice versa?