So I know that there are no promo codes for in-app-purchases in iOS. What I am wondering, is will Apple reject this mechanism:
Provide two in-app purchases, one
I had same problem... so I called to the apple developer IAP helpdesk and they redirect me to email the App Store Review
section.
Next day they wrote me:
We understand that you would like clarification about a business model you are developing for your app.
We are unable to provide pre-approval or guidance on app ideas or concepts. After you have submitted your app, we will provide feedback during the review process, if applicable.
So I wish you luck... There is no one clear option