I don't know why Greenmangaming.com doesn't get more love around here. They are currently offering 15% off Borderlands 3 Regular / Deluxe and Season Pass PC Version.
They also sent me a unique code tied to my account for 35% off Super Deluxe version, you might have to register to get a code.
Cheapest Price I have seen it for PC so far.
Code for 15%: AUTUMN15 - Looks like it applies to all RPGs on their website.