Is it ok that Amazon kindle put that book free for reading after that people here pay 99 dollars to get a copy?
If you mean is it authorised by BALG, it is, it’s on Kindle Unlimited, I don’t know what the T&C’s are for that, looks like it’s $9.99 a month (so, not “free” as such).
Edit to add usual disclaimer I don’t work for BALG or represent them in any way, just volunteer forum mod btw.
I’m ok with it. Think of the physical copy as more of a collectors item. Though I don’t really get why an electronic copy is still 60 dollars normally. Better to buy the paperback for cheaper…
Kindle Unlimited isn’t free.
It’s a monthly subscription program, where you pay a monthly fee to access books in the program. Your access remains as long as you keep paying.
If you read a lot and don’t need to re-read the books, it’s fine.
But for a book like this with takes many months to work through and acts as a reference thereafter, it’s cheaper to buy it.