CarrionCrow: Refreshing the page repeatedly, but it's still not changing. Either the item's broken, or the developer only wanted their stuff to be 75 percent off for a certain amount of time.
HypersomniacLive: Or it took the place of a title that was discounted at 50% and GOG failed to update all details. It's not like it'd be the very first time they'd have messed up. ;-)
EDIT: Based on Pdigeot's script, last time that
Moebius: Empire Rising was around it was followed by
Lifeless Planet: Notice anything?
Moebius: Empire Rising $8.99 ($29.99) [70%] (Ends Sun, 07 Dec 2014 19:18:59 UTC)
Lifeless Planet $9.99 ($19.99) [50%] (Ends Sun, 07 Dec 2014 19:58:59 UTC)
HypersomniacLive: Took a couple of rereads, but i get what you're saying now.