Paul, you may just be surprised at how expensive a roll of Tri X is in Australia. Vanbar, which is one of the biggest photographic retail suppliers in the country, are currently listing it at just under $13 USD; quite a few other places are more expensive. Last week I ventured into a store where Tri X was retailing for $19.99 AUD which equates to $15.34 USD. It seems to me, that Kodak film in this country is priced to not sell.
This is quite a reversal from the days when Kodak film products were almost always keenly priced and much lower than Ilford; with Fuji film about in the middle. I'm talking B&W negative film here. Currently I see Ilford film cheaper by far in this country, something I never thought I would see as it has been more expensive than Kodak as far as I can remember. I am mildly surprised to also see Ilford film cheaper than Kodak films in various parts of the world
As for Costco, never been inside one and I have a problem in understanding why I should pay to enter a store to maybe, just maybe, purchase something. I have no idea why someone would belong to a Price Club; no wonder they changed their name.
As I am away for a couple of months, carrying enough film may be problematic, not impossible; I have done it a few times. It is, however, nice to know, that if needed, I could purchase film that I know, like and understand, locally.
Mick.