I paid what it currently says on the website, which is US$375, and I think US$53 foe economy shipping. Although I did get hit with 18% duty and GST when it arrived - you maybe able to get away with 3% duty if you get them to decalre it as vintage car restoration parts (which is something i've since learnt). I bought when the AU$ was approx. .50US so it probably ended up costing $900 or so. You could probably get it in now for like $700 or so (just go to
www.xe.com/ucc and convert US$425 to AU$ and then best case scenario multiply by 1.13 for duty/gst and add $50 for customs fees - that should get you close).
I was at first apprehensive about ordering from OS but it does give you so much freedom and saves you an AMAZING amount.
Also what are you building with the T4? I have found that if you are switching to T1 journals then you can maybe use 96.52mm VS Commodore pistons which have a 22mm pin and a super low pin height coupled with the 78.4 crank to build a near stock-width 2.3L. That is what I have done - although somewhere along the line I got frustrated by the lack of a decent exhaust, and built a T1 to whet the appetite. The T4 should get humming again though early next year.