You can get one of the best foreign exchange rates in Singapore at Mustafa. This is in the Mustafa Centre in Little India. 145, Syed Alwi Road to be precise. The Mustafa Centre is a big shopping mall with stacks from floor to ceiling of all kinds of things from shoes to laptops to curry masala to ...you name it. Its' there. It has to. Infact its' so full of things you really can't turn around much. And its open 24 hrs!!!