Amanda,
Thats interesting - I hadn't made the connection between communications and taking payments until you mentioned the two together.
I was suprised when I delved a bit deeper that it looks like at least 10% - 15% of our messages relate to something that needs payment from parents and that excludes all the dinner money chasing we have to do.
Any idea how Parent Pay with comms stacks up vs ParentMail with Payments?