I am certain that 'LK' is a DHL courier number...

Cost from Aust to USA for full tracking through AUSTPOST is over $45! If the item is worth $100 or so its not really viable for a seller if HE pays... especially for multiple items overseas over the course of a year... seller go broke... happy if the customer wants to pay the $45... not many will...

I am certain that 'LK' is a DHL courier number

Was it NINE YEARS ago when this thread was current and postage was considerably less?

And what has it to do with the CURRENT cost of posting from Australia to the US?

We post parcels frequently from Australia, with tracking.

Tracking for most parcels starts with LK (presume DHL, as used by Australia Post). Then 9 digits, then a two-letter country code at the end. For us, AU, but a parcel posted from United States will have US.

However NINE YEARS ago, when this thread was relevant, LK was a USPS prefix, and thus irrelevant to posting from Australia.