Originally Posted by Lemonhead 
My guess is that another 50,000 people will buy the game when it's released.
Your pessimism is unwarranted, "Wasteland 2" isn't going to be a no-budget indie game or an obscure release that no one will notice.
I'd be surprised if it didn't sell at least 500K copies in a short amount of time. Witcher 1 sold 400K copies in 2011, 4 years after its release.