(Paraphrasing, of course)
"Do you have the Witcher 2?"
"No, I have 1. Still in its box."
"It's on huge sale at GOG."
"Oh. Huh. ... yeah, but I have a zillion games in my backlog already. I have never played 75% of the games I own at GOG."
"If you have 1 you should get 2."
"I have had 1 for almost two years and still haven't played it. And I only have 1 because someone bought it for me, I think. If someone wants to buy 2 for me sometime, cool, but otherwise I should restrain myself to things I have some slim chance of using."
"It's only cheap today."
"It'll be cheap again someday."
"... this is true, and something these sales rely on you forgetting."