How many were you after?
They cost £4 each here (incl. tax), with shipping to the UK being around £2 each, unless you're talking about dozens of them.
Alternately I'll ship you a quantity in exchange for a PA160.1 core.
Unsure about shipping arrangements to Australia for you - typically these things are done by weight here in Oz, unless you're talking about "buying" a portion of a shipping container.