Best (or cheapest) place to buy mobile phones in Singapore?

I'm planning to buy a new hand-held phone and bring it back to my country. I've heard that SIm LIm and Lucky Plaza offer cell phones at cheap prices. However, I also read horror stories of people getting ripped off at these places. Are there alternatives where one can find bargain prices for mobile phones? What about Mustafa, Best Denki, Harvey Norman, etc? Where do locals go when they want to buy brand new unlocked mobile phones? Or should I just risk buying a new phone at Sim Lim or Lucky Plaza?