I am a semi-pro gamer and i was looking for a new mouse.Currently I use logitech m90.I generally play FPS games like battlefield 3,call of duty black ops 2 etc and third person games like gta 4,tomb raider,batman arkham city etc.Now the first thing what is a mmo mouse?(I even dont know what is mmo.) Whileplaying fps games,can I assign a programmable key to w,a,s or any other key? and if I can assign can I use them while playing my game to move ,shoot or to carry out any other task?My budget is around 70$.(I can increase it if required)