I think there are three separate questions being discussed here:
1. Is one mouthpiece enough?
2. How can I experiment to find gear that I like without wasting a lot of money?
and
3. Is buying lots of gear a bad thing for beginning/intermediate players?
My personal answer to question 1 is
"A single mouthpiece is not enough for me." This is for two reasons - firstly because I am not a good enough player to use the same mouthpiece for playing classical quartets and for playing gutsy bari in the big band, and secondly because different mouthpieces sound and feel different and I like the variety.
My feeling about question 2 is that it is difficult. Trying out mouthpieces in a shop should help, but my experience has been that the mouthpiece feels and sounds different when I get home. Other people's views can also be very useful, but the choice of a mouthpiece is very personal. I have found Steve Neff's (
@Neffmusic) reviews very helpful, not because I think that buying mouthpiece X will make me sound like him, but because I can compare mouthpiece X to mouthpiece Y as played by him. If X is a lot brighter/darker/pinker than Y when he plays them then there is a fair chance that the same will be true for me.
Buying used mouthpieces and then selling them on seems like a rational approach to me. I know that playing a mouthpiece for a week or two is not going to tell me everything I need to know about it, but it will tell me a lot more than playing it for 30 minutes in a shop. Passarounds are also useful.
Question 3 is more contentious. Some experienced members (I call them the "Puritans") will say something like this:
"Constantly changing your equipment is a distraction and it will slow down your development. If you are a beginner, then you should get yourself a beginner sax and a Yamaha 4C mouthpiece and practice long tones for 10 years. Then maybe (only maybe) you can consider changing your equipment. That's how we started and it worked for us. So that's what everybody should do."
This advice may be appropriate if the goal of the beginner is to play like the Puritan as quickly as possible, but not all of us have the same goals. In my case it's the journey that matters, not the endpoint. I am willing to take detours and backward steps if it makes the journey more fun. So frankly I don't mind if buying more mouthpieces will slow down my development, and I rather resent being lectured about it by anyone who doesn't understand my point of view or my ambitions.