...I totally agree, I'm a woodwind tech, and (in the interest of getting quality horns into middle school programs) spent some time during the pandemic looking at the cheapest way to generate exceptional-playing clarinets and alto saxophones for the schools.I believe that it is best to obtain top notch equipment, that way you can rule out the gear when your progress not up to par (that means that it's the player )
The good news, concerning Clarinet, is that a good used Pro model is available at a reasonable cost.
I've found Selmer Series 9 Clarinets to be available for ~$500.00 or less on Ebay. Even if a re-pad is needed, it's not a big deal since your fingers are used as many of the pads (on all Sop Clarinets with few exceptions). Some Series 10s can be reasonable also. I have never studied Balanced Tones or Centered Tones but I'm sure they can be had at a reasonable price. Also, the Selmer 9* is a Buffet style Clarinet.
I don't think ligs make much difference, but I do like the ones that can be attached and removed easily. I'm not sure a strap is needed, as the Clarinet is very light, I do like to use a padded thumb rest though. Syn Reeds (I use Fibracells) are fine, esp for practicing IMO.
I focused on <shopgoodwill.com> as my source for the "substrate horns"
e.g. you can get a solid (but unplayable) Yamaha YAS-23 alto sax for <$200, put 4-6 hours and $50 into it and have a very nice playing horn
Clarinets are the big value...I started out looking at familiar brands, but most sold for over $100 and were in bad shape.
After looking for a while, I found two horns that are plentiful and represent large bore and narrow bore horns:
Boosey & Hawkes 1-10. A large bore bakelite (synthetic) horn with very nice intonation, big sound (free-blowing) and generally available for <$20-30. I have placed >25 of these into middle school programs to great success.
Vito model 7214 and model V-40...these Vitos got the most advanced LeBlanc "jump trill keys" version of keywork from their professional offerings. These are the last plastic clarinets that Vito made...the model 7214 is a (mostly) cylindrical design and the V40 is a polycylindrical design with undercut toneholes and several other bells and whistles. I could get these in tip-top shape for about $100-$150 out of pocket and 6-8 hours on average.
I have kept both a Vito 7214 and a V40 in my personal collection (with nice cork upper and leather lower pads) for playing outdoors and/or in risky situations (my other clarinets are a Selmer Series 9, a Selmer Centered Tone and a Yamaha Custom SE).
To the point, however...I have, over the past 3 years, completely switched over to Legere reeds...following them through several generations. While I still play the "Classic" reeds on Baritone sax (just works) and soprano, I have upgraded to the Signature Series for clarinets (bass and soprano) and the American Cut for alto and tenor Sax. I have no regrets and don't feel that I have compromised tone at all and have gained some in dynamic range with the European Signature and American Cut offerings (compared to cane).
There was some discussion here also about clarinet ligatures. Like many folks here (likely) I have collected several (understated!) ligatures, and find that I just get better reproducibility and easier reed mounting with the rigid (metal) ligatures vs. the fabric (e.g. Rovner) ligatures. I have become partial to the Bonade Inverted design...it is simple, solid, clamps the reed from the center (i.e. symmetrically) and gives me more reproducible projection over a wide range of mouthpieces. It's also really affordable!