DRM is scary. I am concerned.
Every book I own is mine. I can see it, feel it, read it, lend it to anyone I like, for as lont as I like, sell it for any price I like. There are restrictions - e.g. my DVDs can't be loaned for profit, but I can loan them to a friend for a week if I want for free. I can leave my collection of books, CDs, DVDs, Videos, Cassettes and even Records to my kids when I die.
Every photograph I take, video I make, is all available in nice digital formats. I put in effort to make sure there is standard versions (I shoot RAW but keep an output as JPEG) on standard file systems on standard media all the time. I don't just keep copies on DVDs or other media that can be lost, but instead keep a large set of data that I move between systems. My collection of personal content is just over 1 TB, so I can still do that - and it is growing only about the rate of disks. This means I will also have a great collection of owned digital content I can give to my kids, sell, lend or what ever I want.
Original records are actually going up in price. My tapes may be a bit static (see worthless) but I still use them.
Digital books, instead of printed books, are often a little cheaper than the printed version. I say a little because they are not much cheaper. Some are more expensive, and some are even half the price, but it is rare to be better than that. That said now lets look at the maths.
Retail store takes between 40% and 60% of a book price. This make sense. Books are not particularly expensive items, and there is rent, GST, Tax, Super, Insurance, Wages and lots of other overheads. So straight away a book should be half the price electronically. Then we have cost of printing, cost of delivery. This is a bit more, but I can't work out the exact price - at least 10%. Finally there is the marketing costs. This is the same electronically or paper. You decide then to buy the electronic book for half the price, and save the world by not cutting down another tree.
Each time I buy a new Terry Pratchett it gets read by all the family members. But wait, some of my family members don't use Amazon, others use Apple Books, and another Google, another has none of the above but still electronic tablet and one only reads physical books. Only recently has there been the ability to 'loan' books, but it only works within one walled garden - ie. Only Amazon Kindle can share with Amazon Kindle. Can I leave my digital books from Amazon to my family. What about in 100 years, will Amazon DRM servers be still running then?
DVDs are the same. We buy them. We don't download illegal movies, we buy the DVD. We then share that DVD with my family. iTunes Movies are more expensive than buying a DVD. Yeah you get them straight away, and it saves me converting them to MP4 - but then they are locked to only me, forever. I can't even take one up to the Snow and watch it with friends.
Insurance? My house gets robbed, I loose my books accidentally, a fire burns down my house - in all cases I get my collection restored. Well at least the money I would need to restore it, as some are not replaceable.
But if you have DRM content... this can happen to you: http://www.bekkelund.net/2012/10/22/outlawed-by-amazon-drm/