These sales are quite common. In my moderator capacity, I've changed the title of this thread to match those from other similar sales; you can search this forum using the first few words of the title for past sales. Although I think they've gotten so common that no one may have bothered to create threads for the last few.

I think the advice from the community is fairly consistent that if you have specific travel plans and you see flights currently available that you can book with these points, a purchase can be worthwhile, but the valuation isn't all that compelling compared to other methods of acquiring points, so it's not great to buy them just to sit on them.