Bought my Logitech 2.4 GHz Cordless Presenter at PK Computer at VivoCity for S$132. I have no idea why presenters are so expensive. Even those non-branded one cost about S$80. But I must say a presenter is a good investment, I can use it for presentations in my school as well, save me the hassle from clicking the mouse to change slide. I love the Logitech Presenter because it has a built-in countdown timer which many presenters lacks!
Official Site: Logitech 2.4 GHz Cordless Presenter