I agree with you: if you get 200 rolls at the time it is worth the shipping cost. But to do that you need to spend, let's say on average, $850 upfront. Plus, storing properly 200 rolls in the tropics is not that easy, unless you shoot 2 rolls per day on average and finished them all off in 3 months (which is not my case, unfortunately). For a non professional user (or somebody who simply alternates digital and film) it becomes trickier.
So shipping inevitably has an impact.
I am based in the Philippines (almost no film available locally). I am looking at buying lets say 40 rolls at the time, 1/4 bw, 1/4 slides, 1/2 color prints, on average.