Look at the price
Fanatical has set and compare it to Steam. I guess they wanted to follow the new pricing that Activision Blizzard has set for their games but forgot that most people are not that gullible or else those keys would have been sold instantly. Huh, maybe I am missing something here because
GreenManGaming is doing the exact thing. From my experience with GreenManGaming they don't usually do that, so I wonder if it is because of this particular game. Interestingly enough CDkeys has the price closest to Steams retail price and the largest discount. That is kind of ironic since it is a more shady marketplace, but they are being the most honest.