Sadly, the Official IAP is only for one time purchase items:
For IntelXDK Crosswalk Export
You can use Cordova IAP from cranberrygame to make consumable items.
But it is a paid product :
Also, how can I display the product price converted in native currency format of the user/player?
It is already automated by google play. You just need the plugin for C2, Cordova IAP plugin, I mean.
For Cocoon.IO Export
A small tip:
The stable one for me & easier to manage is the IntelXDK export with Cordova IAP plugin. That is only my opinion. I've tried both and I find
IntelXDK to much more stable. But it is paid though.