What I find more disturbing is that most shops don't adjust their margins to a lower level. OK, they need to account for increased prices too, but is it really necessary to make a 50% profit on a roll of film, if that film increased its price from 1 to maybe 7 dollars in a few years?
50% of 1 dollar was 50 cents, now they earn 2-4 dollars on each roll sold, which just sounds like a ridiculous change to me , and forces prices upwards even more.
Normally, with higher priced products, margins seem lower. Certainly cameras are no longer sold with 50% margins as they probably did 15 years ago, more in the range of 5-10%.