Pre sale billing scheme

we are integrators who consider Baicells, however, reading the billing scheme for the cloud charge of $1.00 per SIM us a to a rejection level.
we are planning to buy a license for 100,000 users. it is not economic for us to fork $100,000 perpetually.
do we must use the cloud core or still can use 3rd party billing?

If you have a Local EPC, then you do not need to use Cloudcore.