1. For math textbooks, being “open source” doesn’t really add much value (compared to just free).
2. Don’t limit yourself to free textbooks. I would urge people to not hesitate to pirate PDFs of good, non-free textbooks if you can’t afford them or find them too much of a financial burden (textbooks are usually outrageously priced in the U.S.) A good textbook vs a mediocre one probably doesn’t matter for entry-level topics (think freshman, sophomore, or even junior level topics for math majors), but for advanced topics, good textbooks can be markedly more insightful than a mediocre one, or sometimes you need to approach the same topic with different mindsets by learning from multiple texts.
> For math textbooks, being “open source” doesn’t really add much value (compared to just free)
That is wrong. For one thing it allows someone to take up a project if the original author dies.
> I would urge people to not hesitate to pirate PDFs of good, non-free textbooks if you can’t afford them or find them too much of a financial burden
That is also wrong. Authors spend a significant part of their lives on a book and are entitled to do with it as they like. The best way to get free access to a for-cost text is to use your library. (BTW, I write books that are freely distributed.)
> it allows someone to take up a project if the original author dies.
Sure, in theory. In practice I’ve yet to hear of a worthwhile monograph in mathematics written that way.
> The best way to get free access to a for-cost text is to use your library.
Not all libraries stock for-cost texts of advanced mathematics. Not all people, including gifted high schoolers, live anywhere close to a library. These are especially true in poorer countries. When people make remarks like yours underprivileged demographics always seem to be forgotten.
Anyway, readers can do with the Internet as they like, and sorry if you’re offended.
> That is wrong. For one thing it allows someone to take up a project if the original author dies.
I've also heard that it also makes it easier to get it professionally printed and bound if one so desires, as printing services are otherwise wary of infringing copyrights.
The price of textbooks is also wrong. If people could make a living from writing textbooks in 1970 that would be the equivalent of $30 today I don't see what's changed that they need to charge $300 for them.
In 1976 I bought copies of Apostol's "Calculus" for $19 for each volume new at the Caltech bookstore. These were published by Wiley.
That was for the 2nd edition of Volume 1, which came out in 1967, and for the 2nd edition of Volume 2, which came out in 1969.
$19 in 1976 dollars is about $86 in 2019 dollars.
Apostol's "Calculus" is still available from Wiley, and is still used in a few schools for their proof-oriented calculus courses (Caltech, MIT, Stanford, for example).
Wiley wants $283.95 for the current edition of each volume.
Guess what edition they are up to now?
The answer is the 2nd edition, from 1967 for Volume 1 and 1969 for Volume 2. They haven't even given them a new cover design in the last 50 years as far as I can tell. The design on the new copies today are the same as on my 1976 copies. All they've changed there is lightening the shade of the background.
(NOTE: this means that there is no downside to buying the international paperback edition. Sometimes publishers keep the international edition a few years behind the American edition, so for frequently revised textbooks the international edition might not match your course. Not a problem with these books. The international editions can be found for around $20 per volume, including shipping. Abebooks is a good place for this).
So...what changed since the 1970s to explain the $283.95 Wiley wants for these books instead of the around $86 we might expect based on the 1976 price?
The other big name in proof-oriented introductions to calculus, Spivak's "Calculus" was $70 when I bought a copy of the third edition in 2004. That one has had one new edition since then, which is currently $100. $70 in 2004 would be about $95 in today's dollars which is close enough to $100 that I can believe that one's price is explained by inflation plus revision costs for a new edition.
But for Apostol, where it's all just reprints of 50 year old books, I can't see anything other than "because we can" to explain the price.
The international additions cost less than $30 and are profitable enough to print.
So what's changed since the 1970s is that the market has been captured and book publishers can charge anything they want for books because you fail the class if you don't have the latest book with the one time use code for the exercises on the website.
> (textbooks are usually outrageously priced in the U.S.)
When it comes to textbooks, with a few exceptions, math textbooks are a lot cheaper than other technical fields.
Maybe not the ones your university is requiring for introductory courses (e.g. Stewart's calculus), but there are plenty of cheap, equally good calculus textbooks out there.
The main exceptions are Springer-Verlag text books. And even some of those are not too expensive. I'm looking at one of my analysis text books - it's $36. My grad level abstract algebra textbook is $47 (also Springer).
Almost everything by Dover is cheap, and many of them are excellent books.
In general, if your goal is to learn, and are not required to buy for a class, math textbooks can be had for relatively cheap new, and fairly cheap used.
Sorry, coming from an engineering background, everything in mathematics looks very affordable. Occupational hazard :-)
2. Don’t limit yourself to free textbooks. I would urge people to not hesitate to pirate PDFs of good, non-free textbooks if you can’t afford them or find them too much of a financial burden (textbooks are usually outrageously priced in the U.S.) A good textbook vs a mediocre one probably doesn’t matter for entry-level topics (think freshman, sophomore, or even junior level topics for math majors), but for advanced topics, good textbooks can be markedly more insightful than a mediocre one, or sometimes you need to approach the same topic with different mindsets by learning from multiple texts.