If you do a lot of international post I'd check out SkippyPost too. They are an economy airmail provider operating in Australia and are a lot cheaper that AP. They work with Singapore Post and even using their slightly more expensive tracking service its still cheaper than APs standard Airmail price.

Normal Skippypost can take 10-20 business days to North America and up to 12-24 business days to the UK and Europe but the Skippy Tracker service hooks into Singapore Mails Speedpost service and its 7-10 days for delivery. Well worth looking into - I've used them for years.

I sent a 140g parcel off to Turkey yesterday using the tracker service. If I used AP Airmail it would cost  $20.20 for standard airmail, $27.20 for Registered (no tracking). SkippyTracker cost me $16.83 which is $7.83 for the service and a $9 shipment fee. You have to send your parcels to Skippypost in Sydney and then they dispatch them.

They apply a standard $9 fee per shipment which covers the reply paid label which you attach to your shipment. - send 1 parcel = $9 shipment fee - send 2 parcels still the one $9 fee. You can send up to 20kg of parcels to them in one shipment for the one fee (which is discounted to $6 (or thereabouts) if you send 3 or more parcels in the one shipment).

....and no I don't work for them but I am a satisfied customer