I chose "never". I pre-ordered the game, I'm not going to wait for it.
How can't you justify it? It's one of the cheapest things you'll ever buy!
I paid, $100, maybe $120 for Civ 5 (plus DLC/expansions) and I got more than 1600 hours out of it. So the game has cost me at most 7.5 cents an hour.
I can't think of any other recreation, apart from a walk outside, that's that cheap!
I work about forty hours a week for the money I use to buy video games, and I have lots of other things I like to spend money on, to say nothing of expenses that aren't a matter of choice.
So for me the calculation is different.
I don't understand the obsession so many people have in getting a game you love for cheap.
I'll give you a hint: some people have to pay rent, for food, and other expenses, leaving less for video games. Moreover I have other things, some of which also cost money, that I enjoy doing as much or more than playing video games.
Second, applying this criteria in life would lead you to never go to the cinema (most movies will be available on tv for free in 4 years time), never buying a book (download the pdf on the web or take it at a public library) etc. and this will end up in ruining your life for what? Having spared $ 20 here and there? To buy what?
In fact, I do buy books here and there but otherwise this is a perfectly accurate description of my habits with regard to these things. Somehow, I don't feel that this 'ruins' my life, because there is more to life than books, films, and video games. I mean, really, paying $20 to see a movie in the theater is like burning it as far as I'm concerned. The last movie I saw in theaters was The Force Awakens and that was a mistake. The last one before that was the final Harry Potter movie and I didn't pay for it.
If you are a young person whose parents still pay most of your expenses, or if you have a job where you don't have to work too much and you make enough money to support routinely paying full price for these things, good for you: most people aren't so lucky. And most people have other things they like to do that cost money that aren't watching movies, reading books, or playing video games.