I wonder if anybody knows of any European market general use fluorescent lamps that have suddenly become “rare” and “collectible” in 2024 after being common in 2023 thanks to the EU wide ban on fluorescent tubes were they have been in common use for a long time, but are suddenly extremely hard to find nowadays.

The lamps in question that I am talking about here include formerly common European market fluorescent lamps that have been discontinued in 2023 that are now extremely hard to find nowadays to the point that they are almost nonexistent.

Not near extremely rare here. Widely available on the second market as no one wants them. That mostly includes uber boring 36/18W T8 halo types, though from time to time something really funny surfaces, as my Aura lamps. I owe a post of them!

For me, as someone who lives in the USA, I always find the 36W and 18W T8 tubes quite fascinating.

Netherlands:
The biggest DIY store does not sell any fluorescents at all anymore, except for Sylvania 840 circlines. The last tubes they had were 827 and 840, in 18 and 36w. They sold the remaining stock for €2,50ish per tube.

All others, only a few 827, 830 and 840 linears. But it's old stock, and no one really wants them since the LED tubes are equal in price (10 euro a piece for Philips branded tubes, give or take a couple euro depending on size). Power between 18w and 56w.
There are also a couple ultra cheap and shitty slimline fixtures with 865 daylighttube left. Interestingly those were not delivered with an 840 tube - color 865 is highly unusual here.

Halophosphate is unobtanium here. But with the exception of color 640 (that one has been available right until 2 years ago), that was already the case for over a decade. Color 530 (29) already was gone since the late 2000s. This also goes for webshops.

On webshops, all common t8 and T5 sizes are still easily available. T12 is close to unobtanium, though TL-X (explosion free) ones are still available in 40w 640.

Interestingly enough, *because* of the ban and the LED 'takeover' i've actually been able to acquire the lamps i want. Loads of fully functional fluorescent tubes go into the recycle bins because people are now often replacing a broken fluorescent with a completely new LED tube or fixture, so their working spares end up in the recycling where i can pick them up. I have a couple Deluxe halophosphate tubes that are 100% unavailable at retail, and also don't show up on dutch online 2nd hand sites.
Once in a while something fun shows up at the thrift shops, where people sometimes bring fully functional fixtures. So i was able to get a 15w daylight halophosphate tube, and one or two conventional color 29 (530) tubes in sizes i use.
I fiercely hope some 40w T12s in that color show up some day.
The sad bit about that, is that i had to let go another Electrofar and a 25w Daks t12 tube, simply because i cannot stash them away anywhere. I do pick through them, and if i find deluxe stuff, i will still take it home... I do still regret that, and also not taking the T12 daylight tube with me. If only i had more room. The annoying bit is that right now is the time to stock up, because it'll have to last the rest of my life.
I'm perfectly happy with the efficiency of fluorescent tubes, so that's probably what i'll light my house with when i get one.

Finally, i'm gonna visit one very old lighting shop that opened somewhere just after WW2. They still sell loads of incandescents. I'm gonna ask if they happen to have some halo tubes left.