Personally I've never felt the need to drop tons of cash on a mouse. I've been playing games with pretty basic mice for a long time and they work just as well.
That's not to say I'd stick with a
bad mouse, because there is certainly such thing. I've used some off-brand mice, usually small portable ones, that track poorly. But right now I use a Microsoft Intellimouse Optical from probably 10 years ago. If I were to buy a new one I'd probably just get
this Logitech for $20 from Amazon. Don't see the point in spending $80 for a "gaming" mouse unless I'm a professional gamer or something.