Regarding the co$t of digital cameras:
When Gillette introduced the "safety razor" - the one your grandpa used that took replaceable double-edged blades, called "safety" because with these blades properly installed in the handle you could not slash your throat inadvertently... but I digress. My point was that Gillette knew that if he priced the handles at a "bargain" price he would develop a great crowd of customers who would be committed to buying the disposable blades over and over and over and over again.
George Eastman had a similar insight when it came to popularizing photography for the masses. He sold the cameras at a relatively low price, knowing that those customers would have to buy film over and over and over and over again if they wanted to actually get photos out of the little magic box.
Now with digital photography the game is changed just a little. You don't have to buy film - the electronic detector is ALL THE FILM YOU WILL EVER NEED.
BUT! You DO need to buy bunches of batteries to keep those electronic circuits "alive." Note to self: devise a solar cell that can be used with digital cameras to reduce the amount spent on batteries.
But then there is night photography... LUNAR cells???