Hmm. I'm wondering where that $8 (!!) for a roll of T-Max (135/36) figure is coming from. We're talking about US Dollars, so the Australian dollar would be around that, but not what I can see. Prices do vary considerably.
Have you noticed that some colour film stock, Fuji among, has gone up since the beginning of this year? What else has??
T-Max 100 135/36 only $5.95 where I get it. And Portra $5.35/ 4x5 sheet (which I do not use). It might be down to a lack of competition at a retail level.