Digital cameras are responsible for many wonderful things. They let us capture manner of events that were not practical or possible before. They enable us to post-process and alter our images quickly and easily. They make it possible to share our images with just about anybody at no cost and little effort.
What they have not done, at least for serious amateurs, is save us money over their film predecessors. This of course flies in the face of conventional wisdom. No more buying film. No more paying the drugstore to process our images (or buying the chemicals and equipment and processing them ourselves). No more paying for prints of every image on a roll of film. Etc.
So why haven’t they saved us money? Well for starters, there’s the computer. If you want to process your images, you need a computer, preferably a reasonably fast one. You need large disks to store and back up all those images. You need software in which to do the processing. And these are all consumables – which means that over time they must be constantly updated and replaced.
Then there’s the matter of the cameras themselves. Today a good mid-grade DSLR with a good lens is around $1500-$2000 (e.g. Nikon’s D7000 + 16-85). A good mid-grade SLR from the 1970s meanwhile in today’s dollars was about $2000-$2500. Okay, so on the face of it, a slight win for digital.
Except that that 1970 SLR could be expected to keep working more or less indefinitely. Treat it well, replace the battery in the meter every so often and give it CLA (Clean Lube and Adjust) every 5-7 years and you could expect easily 30 years of use without anything important failing. And if something did fail, you could expect to repair it for well under the cost of replacement. The pieces were almost all mechanical and reaily available.
Any DSLR produced today meanwhile is basically guaranteed to be a paperweight in less than 10 years. Parts are difficult to replace, and being mostly electronic, getting replacements is expensive and often not possible (they go out of production).
At the same time, there are more incentives than ever to update on a regular basis. While film SLRs saw few major changes until the widespread introduction of autofocus in the early 1990s, DSLRs are still seeing frequent and constant updates, both in terms of features and in terms of base image quality. With a film SLR, if a better quality film became available, there was nothing stopping you from trying and using it. With DSLRs, improved sensors require buying a whole new camera.
The net result is that most serious amateurs have been updating their cameras every 2 or 3 years. These updates usually require storage and software updates as well, and sometimes also necessitate buying new computers and lenses.
So at the end of the day, while serious photography amateurs have benefited a great deal from DSLRs, they have and are paying for that privilege. Nothing wrong with that. Just don’t let anybody sell you on the notion that you’re somehow saving money in the process.