How to impliment iOS In App Purchase for books with dynamic price?

Question

I have developed an iOS app were user can buy Audiobooks which enables stream and download within the app. I have integrated Authorize.net payment gateway. It got rejected by Apple saying

11.2: Apps utilising a system other than the In-App Purchase API (IAP) to purchase content, functionality, or services in an App will be rejected

So now I want to integrate Apple's IAP. I am very new for IAP. My question is I am having hundreds of books with different price ranges (eg, $1.00, $2.99, $0.99, $5.00 etc..,) the price is coming from server it is dynamic. It is not possible for me to create price tier for all this.

Question 1: How to implement IAP for dynamic pricing?

Question 2: If I am having 4 books with same price tier, Purchasing one will unlock others also (with same price)? If so how to avoid this?

Answer 1

Firstly you have to use the price tiers although you can change the price tier for any given product it must be changed using the iTunes Connect website or the API for the same. It is possible to bulk load product and change prices through the API but new in-app purchases require approval.

Secondly you can have different products available at the same price. Each book should be a separate in-app purchase approved by Apple. That way each one you buy will only give them that one.

An alternative approach might be to sell consumable tokens that can be converted into a book for the appropriate value if you have a mechanism for handling that and managing what they own in accounts that you manage. You might be able to use IAP to purchase the consumable voucher which is instantly and transparently converted to an actual book in your system. I don't know if this approach would meet with Apple's approval though. With this approach you may be able to switch price tiers quicker and more dynamically than you could with Apple's separate products.