$25 is milking gamers? Do you even realize how much regular games cost?
That said, Xenonauts can be preordered $20 from Kickstarter. The regular non-Kickstarter prices of Grim Dawn, Shadowrun, Wasteland are all $20 at least. None of these games will be accepted by GOG due to their dumb policy, because they are all independently-developed games costing more than $15.
Ding, ding, ding, we have a winner. These sorts of blanket policies really only make sense when they extend to everything. Having older games being sold for $20 that happen to have been produced by a major studio makes no sense and some indie games are genuinely worth more than $20. Especially new ones.
I don't know if I'll be buying a copy of the game any time soon, but this blanket policy if it proves to be the case is just wrongheaded. It should apply just as much to major studio releases as it does to indie releases if it's that important.
AC is another example, I bought it for $20 years ago, but it's here now for $20, which is 25% more than what they're apparently wiling to sell a new indie title for, whether or not it's worth the money.