IMO it's not a "bad surprise" to a user that an amazon link is an affiliate one, it's just annoying when the only way you can get information on a book is through affiliate links.
I'd go even further. It's a loud minority that even cares at all about this and they make it feel like everybody agrees with them, but most people don't care and you're totally within your rights to do it. You should go for it!
Clicking through an affiliate link associates future orders for 24 hours, and once an order is placed no further orders are associated. (If an item is added to the cart while associated with an affiliate link it stays associated for 90 days, but it's not clear to me what information is provided to the associate regarding other items in the order if that item is eventually purchased.)
https://affiliate-program.amazon.com/help/node/topic/GPTZ495...