If it's over 100$ it's over priced in my opinion; unless you are a professional gamer or playing for money. I have been gaming for about 20 years and I have never spent more than 100$ on a mouse. I have even won a few 20 man lan parties!
As for what it better? The R.A.T. is pretty crazy looking, and it's a good option if you have really big or really small hands as it's designed to change it's size in like 10 locations. Maximum PC gave the R.A.T. a 10 and a kick ass reward. http://www.maximumpc.com/article/review ... use_ever_0
Personally, that thing intimidates the hell out of me!
They are both very good mice, but I would go for the one that's 80$-Logitech.