I was going to recommend the Coles Lip mic too, but after looking at the initial budget, I decided not to.
Actually, the Coles Lip mic is intended for commentary recording in a noisy environment like a sports arena... It have excellent noise rejection, but it doesn't sound good in terms of the voice quality.
If can push the budget up a little, the Shure VP64A is also pretty decent mic for the price... It's designed as an ENG interview mic, the cheaper version of the tested and proven Shure SM63. Should be in the S$150 range from Hung Bros at Sim Lim.