https://www.pcgamer.com/bethesdas-quakecon-2018-steam-sale-has-begun/

Even though you won't be able to play Fallout 76 on Steam at launch, almost everything else in Bethesda's back catalogue is discounted on Valve's platform this weekend, just in time for QuakeCon 2018. 

While I can't find a dedicated Steam page for the sale just yet, probably because it began very recently and Dead Cells is currently occupying the homepage, you can see the discounts by heading to Bethesda's publisher page on Steam and scrolling down to 'specials'. Some highlights include Prey on-sale for £10/$15, and its roguelite-style DLC Mooncrash for $15/£9.74, which is 25% off. 2016's Doom is just $10/£7.49 (Fanatical has it slightly cheaper), which is reasonable for what's probably the best singleplayer FPS of the modern age.