Microsoft appears to have found an old pallet of Lumia smartphones or something, and it's offering up Lumia 950, 950 XL, and even 650 and 550 models for sale on its web site this month.
The phones apparently popped back up online on February 4, 2018 but per GSM Arena, it doesn't really look like anyone noticed until now. There's probably good reason for that - Microsoft recently gave the kiss of death to the entire phone line, discontinuing support for push notifications for Windows Phone 7.5 and 8.0, with more features and subsequent mobile OSes like Windows Phone 8.1 and 10 likely to follow.
In other words, this is probably your last chance to purchase one of these phones and actually have it be supported by Microsoft for any considerable period of time.
These phones are, in mobile industry terms, archaic. They were launched as far back as 2015, yet somehow Microsoft is still selling them for a fair chunk of change. An unlocked Lumia 950 XL, which retailed for $US649 in 2015, will now set you back $US499 ($637). 950s cost $US399 , while the 650 is going for $US199 ($254) and the 550 $139 (the latter two the same price they were at launch!). While it is vaguely possible that the phones' return to the store means that support for Windows Phone 10 will continue for some time or that it's part of a renewed mobile push by Microsoft, it seems far more likely these were sitting in a warehouse somewhere and the company thought it could get rid of its remaining stock.
While it's possible to boot custom firmware on old Lumia phones, there is regretfully no Android port compatible with all of Microsoft's mobile hardware, meaning users probably aren't going to be able to extend the life of the old devices by porting it to another mobile OS less likely to go belly up. However, some users recently claimed to have gotten Windows 10 ARM running on Lumia devices, though it's not totally clear why one would desire to do so other than bragging points.
In any case, this is your final opportunity to blow hundreds on a Lumia smartphone, if you just have piles of cash laying around and also don't have hobbies, or whatever. Go nuts! No one else is buying 'em. Probably.
Gizmodo reached out for comment from a Microsoft rep, and we'll update this post if we hear back.