HI @richard - we're currently working on a feature that will handle this directly for brainCloud 5.9.
In the meantime, an interim approach would be to:
Manage the Lives in a virtual currency. In the item catalog - you can indicate the currencies to award from the offer via the extra data JSON. And create a post-hook on PurchaseUserItem - calling a script to award the appropriate currencies - and immediately consume the new "item" that was purchased...Just a thought...
[But yeah - we're going to have a more direct solution in 5.9 - which is currently targeted for November release.]
Paul.