As of right now there is an issue with the “Make In-App Purchase” and “Read In-App Purchase” nodes. It seems these issues have been around for awhile and there has been no mention of resolve.
Make In-App Purchase: Always consumes purchase even when “is consumable” is not checked.
Read In-App Purchase: Always fails even when data is properly entered. A fix has already been provided in the answerhub but requires compiling a custom version of the engine.
These issues make it difficult to implement one-time purchases for projects, and properly displaying prices of purchases.
Have you upgraded to 4.10.1? The fixes were added to the launcher version in that hotfix. If you’re still coming across issues after you update, be sure to check out the Android In-App Purchase documentation, which has some example Blueprints, as well as notes about project setup for IAP.