i was looking at the iherb site, seems like they can ship directly to SG. And flat shipping at only US$4.
Qouted from iHerb
International Airmail: $4.00
Orders up to $80.00, and 3 pounds (1360 grams)
Flat $4.00, Free for orders over $60.00!
Very Reliable, But No Tracking, No refund if lost
Takes 1-4 weeks, 10 days to Europe and Pacific
Or pay more with tracking.
DHL - International: $12.00
Usually Takes 2-5 days, with tracking number