I had a chat with a P4P member and it seems that the "one rate" program is for MFP's and not for Print4Pay. Unlimited prints are included for the lease. Not sure of much else other than everything is included in the one price per month.
I did find this on the web last night:
We signed a contract for 5 years to lease a copier. They kept increasing 10% on our lease every year. When we questioned their practice, they said the contract allows them to do it without informing us. It is a very shady and disappointing practice. We are stuck with another 4 months on the lease and can't wait for it to be over. Will never use them again or recommend them to anyone.
I'm not sure if this has anything to do with the "one rate" program, however, if the lease price is escalated by 10% (or more) each month, that could pay for the extras