I think the dynamic pricing algo is on to us - I see $13.99 at Amazon and clicked on a Google Play Books link for $1.99 that then became $13.99 magically, same for Apple Books.
Please don't 'buy' digital items from Amazon, because you won't actually own them. Pay extra, support your local bookshop and get a physical copy which you will actually own.
I think the dynamic pricing algo is on to us - I see $13.99 at Amazon and clicked on a Google Play Books link for $1.99 that then became $13.99 magically, same for Apple Books.