Currently there is no way for a business to have access to the assistant on a pay-per-use method.
For my business, I know already that my employees won't be using the Assistant that much. Making Ultimate for almost all of them unreasonably expensive compared to how much they'd use it.
I know that you might think "well, maybe they haven't yet found a use case for the Assistant but it'll come". And I understand why you might think that, but the thing is that my employees don't have desk jobs, they don't have as much knowledge work as the average desk employee.
