[Fluribus]

Originally Posted by tlc

Three Neal Asher books are on sale at Amazon.com for < $4. But beware: I already had other e-versions of these from Amazon. I really like the fact that Amazon usually stops me from buying something I already have. Perhaps it is due to a change in publisher?

Line War: https://smile.amazon.com/dp/B07H47PVH7
Polity Agent: https://smile.amazon.com/dp/B07H4657RF
Prador Moon: https://smile.amazon.com/dp/B01HU42772

It uses the ASIN. If the number changes for any reason, you will get no warning. Open Road often changes the number when they do discounts. If a new edition of a book comes out, it will have a different number. Changing of publisher would result in a different number.