I'd like to add a bit to the "tools" thoughts. To be sure, and as noted here, a good player can pull a respectable sound out of a Kay or any other "decent" entry-level instrument. A beat-up carved bass with a taped-up hole? Sure, why not. We've discussed many times how player X sounds like player X regardless of the bass that he/she is playing. Of course, it's in the hands and what's of paramount importance is how well the instrument is set up. I'm certainly not a pro-- I've worked on and improved my "sound" over years (thanks to fine teachers) and even I can pretty much pull it out of any DB on which I lay my hands-- sometimes to the astonishment of a newbie player.
Of course, those of us who have the means and desire to play basses above the entry-level grade do so because they sound better and play better and that adds to our musical enjoyment and helps us to express what we want to express. The exchange of energy between strings and a well-carved top provides a "feel" that just isn't there (for me, anyway) on a lesser bass.
IMO, there is, however, a limit. This gets back to the "decent" instrument notion. I think one can take any of the quality, entry-level instruments discussed here every day, provide it with a good setup, and it will be a fine player worthy of many years of learning and progress by any student. No, it won't sound like a better bass would but it will play just fine. IMO, not so with a CCB-- at least not without so much effort that the cost would be prohibitive if not done as a DIY project. Even then, it may not be a stable instrument in terms of holding its setup. Indeed, some folks here have gotten lucky with such instruments but even they seem to agree that it's not a path they would recommend to a newbie.
No amount of reasonable setup work can compensate for poor design (overstand, fingerboard projection, neck profile). Those things can hinder progress as can open seams and an imploded body.
So, yes, in terms of learning to play, it's pretty much about the player and not the tools down to a point where the tools become a huge factor. IMO, CCBs are, in general, below that point.
This is all true in arenas beyond the DB. So what does one do if one simply can't afford a decent DB and saving up within a reasonable time is not an option? I think such situations are somewhat rare but, as was said here before, either rent or, if you absolutely must, then go for the CCB with the understanding that it's the hamster of the DB world (you don't bring it to the vet-- you throw it out or bury it

).
If you needed to bolt the water pump back on your car and get to work but had just a few bucks, you'd buy a $10 socket set at the Dollar Store and try to get the job done before the ratchet snapped and the soft sockets wore down. If you needed to do that on a regular basis you'd get a better set, although you may not by a Snap-on set right away. Sometimes it is about the tools.
