Shopping in Singapore can be a bit hit or miss. Many items can be found a lot cheaper in cities like London or Hong Kong. But if you know where to look there are definitely bargains to be had on certain kinds of items (but not cameras. NEVER BUY A CAMERA IN SINGAPORE!).
There’s one place however where you can be sure of getting the latest models of mobile phone, SIM free and unlocked, for something like 20% less than everywhere else including online, and that’s at Lighting Moon in the Peninsular Plaza mall.
Like most of the shops in Peninsula Plaza, Lighting Moon is run by Burmese and the phones they sell are generally on their way to export for the Myanmar market, but don’t worry, they are standard international versions supporting all major languages. It’s possible to find here the latest devices from Samsung, Sony, Apple (including iPhone and iPads) and most other leading brands. They can be found by the main entrance on the south side of the mall.
Not only are their prices lower than anywhere else in Singapore, but they usually have the latest models days or weeks before anyone else. Note that you should expect to pay cash to get the best price. There are cash machines just outside the mall entrance.