Re: Alternatives to YAS-23 for middle schooler?
the YAS-23 is a fine saxophone. It's quality is good, keywork is better than most student horns, and it plays it tune with itself.
However, it's not what I'd consider a good bang-for-the-buck scenario. They are perhaps the best** student horn* available, but student horns just arent' worth paying $1500+ for considering that there's so many good new or used alto saxophones for $2000-$3000 or less that would fit the profile of a professional instrument.
I would look for a used, but recently maintained instrument that has been serviced into appropriate condition. You'll save a few hundred dollars, have an instrument that plays well (some new ones don't without technician attention) and will have close to the same resale value compared to a brand new YAS-23
Also, I would also look into a used Bundy. These horns were as ubiquitous during the 70s and 80s as the Yamahas are today. Properly maintained, they will be as appropriate for use today as they were then. Objectively, their keywork is inferior to the Yamahas, but you can find them for as little as $400 through retail used. With any instrument, consult your potential director. Preferably, have him or an associate approve of any potential instrument before purchase.
** My opinion
* Student/Intermediate/Advanced/Pro are marketing designations. In reality, they are arbitrary.