You can easily find shops selling Razer mouses in Sim Lim
Square.
Razer Krait - 1600 DPI - SGD$46
Razer DiamondBack - 1600 DPI - SGD$68
Razer DeathAdder - 1800 DPI - SGD$89
Razer Copperhead - 2000 DPI - SGD$105
Krait, DiamondBack and DeathAdder uses infra-red sensors.
Only Copperhead uses laser-sensor.