<Big thumb up!>
I forget of course, that these lenses were of a certain time, and some people might have missed out on knowing about them... But, yeah. A good set of lenses that will work on most lens mounts. Plus, you can leave the adaptors on the camera bodies and swap lenses. The adaptall mounts can be a bit fiddly, but they do work!
I bought most of mine in the last couple of years in the UK. I had a 70-210 one touch zoom with a Nikon mount left over from the pre-digital days which I figured wasn't worth trying to sell for all of £10, so I kept it. I then bought a really nice 35-70 f:3.5 for about £15. Then I bought an older 70-210 macro lens because I wanted the Olympus mount that was attached for £8, which turned out to be a really nice, if not quite large and heavy, lens. And great for macro stuff. I also bought a 200mm for naff all, a 24mm for about £35 and a very nice 17mm for around £60. The 17mm is great and uber wide without any fisheye-ness which I was initially slightly disappointed with, but after using it for a bit, I completely changed my mind! It's a great lens with a great view that is very different to my Nikkor 16mm.
Things seem to have changed looking at current prices on ePrey, but when I bought mine, it seemed that going for lenses with less popular or favourable mounts (such as M42 or Canon*) meant the prices were lower. Looking at current listings, prices seem to have risen, but aren't as expensive as branded lenses. Oh, and if you haven't already found it, check out
https://www.apotelyt.com/photo-lens/tamron-adaptall-catalog
*What? Oh come on! Yeah, look, I know... But, as a Nikon user, I have to take a cheap shot (ha!) whenever possible