The lack of replies is somewhat discouraging.
The Xojo license update apparently costs $299 (plus sales tax of 8.25%, because REAL Software People Who Make Xojo Company is also in Texas).
I did find a way to save 30% though. New licenses also cost $299, but there's a promo code that takes off 30% (but only for new licenses). (If they refused to process the order for some reason, then I would just "move" to another state for a day, and buy it there - and also save on sales taxes).
Or, I could order just the Mac license for $99 (-30%), but that means the Windows runtime would be compiled with an older version. Fortunately, there is no forthcoming 32-bit apocalypse for Windows apps. I could even order the Windows license for $99 and still save over the $299 package.
I'm not asking for donations, just gauging interest, I guess.
I have some thoughts on the current state of GMG/the community in general that I'll post in another thread. Summary: GMG is generational and needs some new faces, but has also been decimated (in my opinion) by bullshit such as "Gatekeeper".