ByWP. Katong Shopping centre basement 1 got one shop carry quite a comprehensive range. Seng Li also carry them. Lensman @ Compass Point also have.
Currently using a pair, but I find the construction very flimsy. One of the hinges got loose after like 1 mth of using, maybe my face too fat stretching the frame. The rubber at the temple ends not as tight keep slipping out slightly.
IC Berlin construction seem better.
If you looking for more budget one, I recommend you to get the similar budget one, saw it at one of the neighbour shops under the brand Hanes. Made of Ti and from Japan but the finish a bit rougher, comparing the materials, I would go for the Hanes if I seen in earlier. Cheaper and better material. One of the shop I seen have is Chew Optics @ Bishan North Shopping Mall.