Get the repair manuals that are out there. Years ago a company (now gone) Eric brand had a good but date general manual. get others as well. A library of about a dozen is a start. Vids are good to. And buy the right tools. I use to buy and fix up clarinets as a hobby. Not hard but not in the same class as Saxes. Try that first too. BUT Juck horns are the way to go. It does not hurt to screw up a chinese knockoff and if you play it you can keep doing the repairs over and over. See if you can work part time at a repair shop too even it is cleaning up. You can learn a lot by watching. Good luck

Speaking as an untrained veteran of DIY maintenance and light repair projects and an occasional repair customer...... With a little basic knowledge, the right attitude (patience!), and a few inexpensive tools, it's not difficult to do a better job than most garden variety music store techs on routine maintenance and adjustment tasks. I've had three overhauls done. One was good, one was ok but flawed, and one was a complete waste because of the tech's negligence. The good one was done by a self-taught tech. That tech was a player who got sick of having to clean up the work of mediocre techs. Do not trust a tech to do work to a standard for serious playing unless they are a woodwind specialist and at least a semi-serious player who can discern the difference between good work and get-by work by testing the horn. Most local techs are not woodwind specialists and are used to cutting corners because their main customers, students, parents and school districts, are more concerned with simply getting something playable for the least amount of time and money rather than something that really plays well. Unless you have a complete lack of mechanical aptitude, you're better off investing in learning basic maintenance and adjustment skills than trusting some sclool-standard tech. Considering the time and logistics of dealing with music store techs, the time invested in learning (and you WILL make some mistakes that you have to redo) isn't completely lost. Start basic, start safe, and start slow. MusicMedic's kit or equivalent and their online articles are a good place to start for cork, felt, spring, and pad work. Follow some simple rules. Do not force or bend anything. If you encounter a problem, get the information and equipment you need to deal with it properly. Repairing issues related to advanced mechanical wear or traumatic damage - soldering, swedging, straightening, aligning, tonehole leveling and such - is the advanced course that you can embark on with cheap project horns.

I don't think so. : )