Hey everyone.

I live in Aus and I'm unsure what currency the GOG store uses. When in the store it just shows the "$" sign but doesn't say if it's Aus dollar or US dollar, I'm assuming it's US but would like some clarification.

Also is there any chance we could get clarification in store? Something like "AU$" or "US$".

Cheers

Both. What is more, you get to choose. At the bottom of the page there should be a currency option giving you two choices.

An example price listing:
$5.99 when paying with USD
A$9.19 when paying with AUD (note the presence of an A)

Also, if you have a credit card with low-to-no currency conversion fees, I would suggest looking into paying with USD until the price matrix gets updated.

A $5.99 purchase at current visa rates works out at A$8.60.

Another advantage of paying in USD is you avoid GOG's insistence of rounding up every AUD price to end with a 9.

AUD (Australian Dollar) is shown here:
https://www.gog.com/forum/general/local_prices_update/post591

As for the confusion between $ and $.. I can agree.
Though if you scroll down to the bottom of any page, you'll see which Language and Currency you have selected.
You could also hover over your username at the top of the page to see and select them.