Amazon has competitive prices.
However, you should be aware that their packaging has recently deteriorated greatly. Their packaging is no longer as secure as before. A member of my family bought some books recently and it arrived badly damaged. You can also find cases of this if you search the forums. But to their credit, Amazon sent my relative a free extra copy of the damaged book.
Imagine your precious equipment bouncing around all the way round the world before reaching you!
I recommend either B&H or Adorama instead. However, I've noticed that B&H has increased their prices for photographic equipment.
The US$ has also strengthened against the S$ recently and so you might want to reconsider your options.