Professionals always shot many rolls of film (remember motor drives?) if necessary to get a single good shot. They didn't worry about the cost of film and processing and they usually carried multiple camera bodies and or film backs for ISO coverage. They could afford to bracket all their shots as insurance. His one film camera cost versus one digital camera just doesn't hold water IMHO.
Film was the cheapest part of the professional's budget--that was the standard, always-repeated maxim. A professional never skimped on film, although to be sure, the usual method was, "See a picture, take a picture." Professionals just went the extra measure to see more pictures, whereas today I think there really is a great amount of "just hold the button down" going on. But shooting a wedding, you didn't count shutter clicks--the limit was how many film backs you could afford to own and were able to carry, not some self-imposed pseudo-moral ethic of click-prudence above all.
The big problem with that writer's comparison of the costs is that most film professionals (not all, but numerically most) did not do their own processing. Those of us who did professional processing and printing can roll in the cost of a professional-level wet darkroom with automated water conditioning and temperature control and air filtering and humidity control, which was not cheap by any means. Start with adding a dedicated, plumbed room to any building budget, and then go upwards with professional level equipment able to efficiently turn out consistent-quality color and black and white archival work, and you're talking a very pretty penny.