You go to those Handphone shop who sells on contract... then ask
the price without contract. They will usually give you the retail
price.
Next is you go to Sim Lim TOWER (NOT SQUARE), then ask around, they
should sell you about 10-15% cheaper.
BUT CHECK ITS CONTENTS.
1) SINGAPORE WARRANTY.
2) ORIGINAL CHARGER
3) ORIGINAL BATTERY.
better yet.. ask for a NOKIA SEALED box.