Thanks for the speedy reply, guys!
I agree. Relying on a third part is probably the best solution.
... So, you're saying it is possible to create a delivery service app with Construct 2, but only if use the Paypal serveice, etc., instead of using the IAP feature. I understand.
Are there any decent tutorials showing one how to integrate websites (iFrame), and Paypal with Construct 2?