Confused on licensing

Can somebody please help me understand the prizm licensing model. I’m about to deploy a canopy network, and need to run the model on costs.

Do I need BAM and EMS licenses for each AP and SM on the network, or just per AP? Do I need only BAM, or only EMS? What does each do?

If I need a BAM and EMS license for each AP and SM this blows my costs out of the water… at about an additional $140 per unit.

Are there other options that do everything Prizm can do? If not, what features am I losing?

Thanks for any help.