I'm using my G700 for wireless FPS gaming and I clock more than one thousand hours on one of my FPS games. This mouse have yet to disappoint me.

One AA battery last for at least 2 days of heavy gaming. You can swap batteries (Energizer for Eloop) and on top of it, they are on the fly rechargable. The wireless receiver doesn't signal loss, great sensor, extra buttons well positioned.

I don't like the wheel scrolling on g700 but it's minor. If my g700 is broken/lost, I won't mind considering getting another g700.

In terms of rm10 mouse vs rm70-90 entry level gaming mouse (g400/mx518), like many of us said, you can totally feel the difference.
Even for my normal laptop, I won't plug in anything less than g400 anymore.

In terms of below RM100 vs RM200-300 gaming mouse, it's all up to how much 'control' you need in the type of games you play. I don't like blaming the mouse cable when/if if my crosshair is not where I want it after doing a 180degree turn. Therefore I chose the wireless g700. If I die, I blame no one.

I'll suggest anyone starting into gaming mouse route to get an entry level gaming mouse and the largest gaming grade mousepad.

state your budget for each individual item if you are asking for recommendations.