Yeah, it sucks. The people who buy those Pop! Vinyl toys have complained about this on the Popcultcha FB page (particularly when 'convention exclusives' snagged by Popcultcha ostensibly for the Australian market get pounced upon by international buyers), but the HT Chewbacca going out of stock is the first time it's really affected me as an issue. I can see above that many non-Australian board members, noting the 20% sale, jumped in to pick up a Han/Chewie set (indeed, some doubling up on the figures given the pricing).
Not owning either, I ordered both - only to be informed subsequently that Chewbacca was out of stock and my order was therefore unsuccessful. So, I have a Han Solo figure, but with little or no chance of obtaining Chewbacca from Popcultcha in future (and, even if so, with an inflated price tag as noted above). Great. So, the only real option for me (given my budget) is to cancel the Han Solo order, redirect that paid amount to another Popcultcha item and forego the Chewie and Han figures. Of course, Ebay Australia has both figures available - for $700. Ebay Singapore, which can sometimes provide an option to Australian buyers given the relative parity of our currencies, has the set available, too - for $700 (plus at least $100-130 for shipping).
I can't necessarily blame people for exploiting currency differences and market protections that suit them, but it's really left a bad taste in my mouth. Knowing that overpricing smaller markets often subsidises cheaper pricing structures in the US, and then to have your local market picked clean of items during a rare 24 hour sale (that provides some relief from a persistently unfair international pricing differential), is...not cool. At all.