I bought Legend of Grimrock on the 50% off sale on GOG a few days ago, and now it's cheaper as part of the Steam summer sale. Not by a lot mind you (1.50$), but still. I wonder who decided in the end about those sale prices. If it was the publisher, then they must have known those would be on sale at different prices, mere days apart. I doubt very much GOG is responsible for this. I also regret not getting the Steam version because the GOG version has no achievements. I suppose the extras compensate perhaps.

I think Steam and GoG are the publishers for Legends of Grimrock. The discounts probably come out of their pockets in order to boost awareness of the title. The GoG version may not have achievements but neither does it have DRM.

Actually, the publisher here is Almost Human games, which is also the developer. Most often, you'll have a developer (the actual creators of the game) different from the publisher like EA, Activision or Ubisoft (bigger entities) that handle most of the other tasks. Gog and Steam are digital distribution platforms.

Am I the only one who was a little frustrated with those sales so close to one another?

Yeah, I missed the 50% off sale and now it is 1/3 the price on Steam. I would prefer it standalone, but hey, a saving of $9 means more games . . .