Dark Souls Prepare to die is on sale now at Gamesplanet for £6.99. Although I got it there other week for £4.99, same price Humblebundle store have it at now.
https://uk.gamesplanet.com/game/dark...am-key--1045-1
https://www.humblebundle.com/store/d...to-die-edition
No idea if will be lower during steam sales, but never noticed it lower than that.