Corsair NIGHTSWORD RGB Tunable Optical Gaming Mouse $49 (65% off, Was $139) + $7.99 ($0 SYD C&C/ mVIP) @ Mwave

CORSAIR-exclusive software automatically detects the center of gravity in real time, allowing you to adjust weight between 119g and 141g and fine-tune balance to perfectly fit your grip
· A custom Pixart PMW3391 native 18,000 DPI optical sensor, adjustable in 1 DPI resolution steps, gives you total sensitivity customization and ultra-accurate tracking
· Built with a comfortable contoured shape that naturally fits your hand, with high-performance rubber grips inspired by pro sports equipment
· Ten fully programmable buttons let you customize your gaming, with the in-game advantage of powerful macros and key remaps
· Includes two sets of weights with six mounting locations, offering 120 different weight and balance configurations for a precisely calibrated gaming experience

The CORSAIR NIGHTSWORD RGB PerformanceTunable Gaming Mouse is equipped with a cutting-edge 18,000 DPI optical sensor, sophisticated weight calibration and a real-time centre of gravity detection system. A comfortable contoured design, ten programmable buttons, and ultra-durable Omron switches deliver first-rate gaming performance. Two sets of weights and six mounting locations allow you to adjust weight between 119g and 141g with over 100 different configurations.

They also had the Corsair K70 MK2 for 60% off but unfortunately I missed out on that one