That thread actually put a stop to at least the buying part. I am very happy with my current concert, and as I wrote I will likely not buy so many more ukes. One plastic, because I dont want to bring my nice uke outside (and we go hiking etc), and one more that's gonna be in low-g. But I am going to wait with that one, and let the research go towards that - and be content with just reading/looking for a while.
I think if I could go back in time, with the knowledge I have now, I would also keep my first ukulele for at least a year before looking into "upgrading" it. Especially when starting out, there are so many other factors that influence the sound and the experience (lack of ability being one of them), and plenty of cheaper approaches to try out (different strings, tunings, getting a proper set-up if needed) that can yield improvement and that don't lead to having too many instruments.
On the other hand, though, going the other way (not to extreme degrees) is also something that I felt benefited me, just differently. I have no regrets and I do enjoy my instruments. It allowed me to refine my preferences more, and it gave me a better idea of what it is that I want from a ukulele -- in terms of sound, construction, playability. I wouldn't have been able to learn that if I hadn't experienced different instruments. Higher-end instruments are a different league, which is both a positive experience and a bit of a curse, like moving from a small place to a large house, or from dial-up to highspeed internet: It's hard to be satisfied with "less" again, because you now know what bigger/better/larger/faster is like even if you weren't missing anything before.
Then again, I believe unless you're into bling, it's possible to get a high-end instrument (sound, playability) at a mid-range price, provided it doesn't have to be koa. Koa makes it more costly. But for other woods, I speculate that you can get a very good quality instrument for around $500. After that (koa aside), the returns start to diminish more noticeably. They diminish before also, but I'm not sure where exactly the sweetest spot is -- it probably depends on the person and what someone wants.
Anyway, for me the biggest UAS contributor was my indecisiveness about the "best" size for me. It's still a factor now, though I'm more aware of it being a bit of a self-deceiving mechanism on my part to justify buying more stuff. If I did it again, I'd get a good concert, and then practice -- no shopping until much later.
But I only know that because of the UAS.