I use a Razor Kraite. I got it in my student days, and it was about R350...really not bad and one of the best investments I have ever made for my PC.
My advice is, find a gaming mouse that you can afford and that feels good in your hand. All the other differences are negligible in my opinion. However, the difference between most regular devices and a gaming mouse is massive.
My Razor Kraite is supposedly optimized for MMORPG's and RTS's, but In my opinion its all marketing crap. Its comfy, accurate and cheap. Done