We use Pharos Authentication to control Scanning to Email from our MFDs but we don't charge our users for the service. We do however charge for Copying and Printing.
I am assuming from what I have observed that Scanning to Email is the equivalent of a copy job as far as Pharos is concerned?
We charge £0.04 per page for copies.
Our Users can happily Scan to email for free - UNLESS they happen to have less than £0.04 credit. In this case the User gets an error at the device stating that they have insufficient funds to continue.
So, ironically, if you are more than £0.04 in credit you may scan to email for free, however if you are less than £0.04 in credit you may not scan to email at all.
Boiling that down: Wealthy? = free stuff | Broke? = Sweet Fanny Adams.
Sounds like a Tory manifesto.