Step back for a moment and think to yourself, realistically, WILL you play it anytime soon? Will you have people to play it with? Most importantly, can you afford to buy something you may or may not play in the foreseeable future?
I'm in no way telling you how to spend your money. I'm just suggesting that you consider some facts before diving from purchase to purchase. Barring the obvious "Ridiculous Sale Deals" reason (which probably trumps EVERY reason I propose below), you should consider the following.
Do You Have the (Frequent) Players
It's a typical question. I mean, if it says it's for 2-4 players, you'll need to have at least one other to play with you. And you may very well do. But the same goes for people who have too many players. If your game nights typically run with 6+ players, then most of those 2-4 player games go out the window (Unless the game has an extra-players expansion or variant). I've had one game night when I suddenly had 7 people arrive, and my stack of 4-player-maximum games became moot. It's these things you'll need to consider, if you plan to get this game on the table. However, if you don't...
Does the Game Have a Solo Variant
Most times you'll want to game when no one else can. Which means your games will just collect dust. They require human interaction, that added sense of competition and backstabbing that only the angry faces of your friends can satisfy. With a solo variant, however, you're free to just blame yourself for failing to win at your own game. Most games don't offer an official solo variant, but some creative fans may post their own in sites like BoardGameGeek.com. It's certainly a huge factor when I make game purchases.
Do You Have Another Game Already like It
This one takes some thinking, but if you can boil down the gameplay mechanics and make an honest comparison, will the new game really add something new? Because, frankly, most games will have the same component types, the same turn system, the same mechanic, and just a different theme or ambiance. Similarities don't necessarily dismiss the purchase of a game if it's a great mechanic with a slight difference. But if you have something close to it that you regularly play, that new game will be in direct competition with that game's playtime. And is that something you're willing to compromise, especially if it's not AS good as what you're playing already? But then again...
Will Your Group Enjoy the Theme
Understand that your collection is yours, bought with your OWN money. But...BUT...unless you're only playing with the solo variants, you're going to be playing with others. And it's important to have the right games for the right people. If your gaming group HATES zombies, then those games in your collection will just sit there and get next-to-no table time. If they don't care for violence or profanity, that's another shelf of games you can't bring. That's not to say you must only carry family-friendly board games, but if you have a solid gaming group and are aware of their interests, smart purchases can increase variety to your game nights, maximizing game enjoyment.
Will You Enjoy It
It's probably the most overlooked question for someone who's about to drop serious money for an expensive board game. But why are you buying the game? Because you WANT it. But will you ENJOY it? They're two different things, and if you can't distinguish between the two, your wallet and game nights are in for a serious hurt. Nothing's worse than buying a game out of "want," only to find out you don't like the gameplay at all, and I'm sure all of us are culpable of this at least once.
In the End...
You may not buy the game anymore. That doesn't mean you'll never buy it, but it just means you're not ready to own a copy. Play a friend's copy. Watch playthrough videos online. Read other people's reviews on it. Do more research in general, and put yourself in their shoes. Even read the negative reviews on it, and see whether or not you agree. It's important to take everything into consideration before you buy a game.
Remember, owning all games may be great, but you'll lose the seductive dance of acquiring it. When you know you're ready, holding that game in your hands will make you less a materialist, and more a collector.