Things to consider before purchasing a game
You'll often read reviews stating you should or shouldn't get a new release because it offers X hours, Y graphics and/or Z features. Sometimes you want to consider these factors, but generally you should disregard them completely.
As sad as it sounds, hype is a very important factor. If an online multiplayer game has no hype, it probably won't have a community either. No point in getting it if you won't have anyone to play with.
This hype factor is also problematic with MMORPGs because it dictates how much time and effort developers will put into it. When a MMO has a better launch, it will often have a larger team assigned to it than if it didn't. Bad marketing signals bad purchases.
Hours to complete
If all you want is the most bang for your buck, you can just play the better free-to-play games. That's as cost-efficient as it gets. Going crazy about how a game takes like 200 hours to finish makes no sense at all, even if it offers great quality overall like The Witcher 3.
Unless you are under an incredibly tight budget or if you have to pick a new game to get for your birthday, this is all nonsense because otherwise a 60 hours game isn't a better buy than a 30 hours title. If you can afford them, you're going to play both anyway!
Okay, so you have the latest and most expensive graphics card anyone can afford, so you want the most realistic graphics available instead of feeling like you've spent too much without reason. That's, in my opinion, an acceptable reason to use graphical quality as reference.
But there are some people trying to make a point around how arcade shooters or puzzlers would offer a better experience if they looked real. That's just not how it works. Realism works for some games and not for others.
Optimization, though! That's really important, specially in a new release. It shows how experienced the developers behind it, it will reach more players and you'll probably have a smoother experience in general. If it can't reach at least 50 fps on your PC then go for something else.
This is what you're really looking for. If a game clearly has the things you love, then yeah, just get it. Just make sure you confirm it really does feature those features. Watch some YouTube let's plays. If you “need” to get it, then by all means, do it.