Here are some pointers and quick tips for those in Singapore buying from Amazon USA.
This is based on my personal purchase experience and reader comments since 2008.
Purchases for eligible items* above US$125 qualifies for FREE AmazonGlobal Saver Shipping
Not all items are eligible. In general, books and discs (music & games) all can ship. Only selected electronics can be shipped.
FREE AmazonGlobal Saver Shipping only applies to Amazon USA
Amazon branches from other countries do not have free shipping to Singapore.
Looking for items that are eligible to be shipped for free
First, create an Amazon account and save your Singapore address with them.
After that, when you visit any product, look under product description, then shipping, for the words "This item is also available for shipping to select countries outside the U.S.". This means that there's a good chance the product will ship to Singapore. Those labeled with "Currently, item can be shipped only within the U.S." would not ship to Singapore.
Second method is to just visit the Amazon Global Shopping page. All items searched on that page will ship internationally.
Third party items fulfilled by Amazon usually do not qualify for free global shipping
Those items are sold by third party merchants. Their items are located in Amazon warehouses and shipped by Amazon. They usually do not qualify for free global shipping because they are not sold by Amazon themselves.
Third party items may be listed in favor of Amazon-sold products
When you see a price on the product page, that price might be from a third party merchant, or from Amazon. If it's from a third party merchant, that means the item will not ship. However, if you dig deeper and look for other sellers on that product page, you might find Amazon listed as a seller also.
Tracking info may or may not be provided
If they are provided, they may not be instantaneous.
Heavy items might have additional weight surcharges
Keyword is might.
Sometimes heavy items do have their weight surcharges waived. So if you want weight surcharges waived, try shipping them via FREE AmazonGlobal Saver Shipping.
Packages above SGD$400 will incur GST
To go around this, simply separate your shipment. For example, you can separate them into $200 each.
If you really have to pay the 7% GST, Amazon will collect the tax on your behalf. You don't have to pay the postman. The tax collected will be shown on your invoice.
Shipping charges are included when calculating for GST
If you're going for free shipping, this does not affect you.
If you're paying for shipping, those charges are included. E.g. $500 ($300 item + $200 shipping) will still incur GST.
Shipping and delivery time
It takes around 2 weeks to ship and deliver.
Usually, it will be SingPost who will delivery the parcel to your home. If you're not at home, the delivery guy will leave you a delivery notice and you can pick up your parcel from the nearest post office on the next day.
Credit card charges and processing fees
This is not shown in your invoice. But according to my calculations, VISA charge 2% to process credit card payments and the banks will charge 1%. So actually, after the currency conversion, you have to pay 3% additional. This is an invisible charge that does not appear on your bill.
Amazon does not accept PayPal payment.
Other things to watch out for when buying
If you're buying something that includes warranty, make sure it's international warranty, or at least you should buy it with the knowledge that it doesn't come with one.
Looking for something to buy for the sake of buying?
Get the Google Nexus 7 (2013). It's the best valued tablet in the market now.
For those buying from other Amazon branches
Read my Amazon Buying and Shipping General Guide.
Here's the Amazon Global Shopping page. Start shopping. =)
Just ask them on my Google+ page