The DLC on discount during Steam Christmas sale, but not on GOG. It seems this is as usual. I regret having bought the main game at GOG now. I'll be more wary in future.

It's the Spring sale, 2023, and so far, Steam has a discount and GOG doesn't.
I'll leave a message in their Steam forum and see if they reply.

Last time this went on sale, before it happened I tried reaching to Teyon where a QA team member said:
"Matters like this are handled by our publisher, Reef Entertainment."
After that I tried reaching out to the Publisher and after 20 days it went on sale, and haven't been on sale since.

oni nechtějí aby to hráči kupovali proto ta vysoká cena a neslevnuji to ....prakticky zde na GOG to ve slevě nikdy nebylo a nebude ..oni máji dost peněz takže je jim jedno jestli to nekdo koupí nebo ne

I remember during the Black Friday sales I saw this wasn't on sale here and looked it up on price trackers. The publisher has only allowed it to be on sale on this storefront twice, and it wasn't on sale this year nor last holiday. It's bad enough when publishers won't let their game come to this storefront for years and years, or ones that release DLC and even just updates behind schedule on GOG, citing fears of keeping the DRM free stuff up to date, but I can't fathom putting it here and refusing to let it go on sale. Maybe we can try emailing the publisher again, but refusing to give a sale price on this storefront feels like you actually want to make a self-fulfilling prophecy of lower sales numbers on it.

Wasn't aware about this DLC until now.

Put it on my wishlist and will wait for it to go on sale.
I got time, even if it takes some more years :)

Busy enough with other stuff and many more other games.

On sale again at Steam, historical low too...

With the lack of attention here, I'm worried the game might eventually be pulled like many others... hopefully not.

Lack of attention because there's no goddamn DISCOUNT!!!!

How do we contact the developers or publishers to have sales on here? Robocop is also on sale here but not this game? That's not fair.

Don't compare that games! Both developed by Teyon, but published different studios. Terminator is Reef Entertainment, RoboCop is Nacon!