I posted this idea elsewhere as a comment, but I'd like to give it its own thread. This is something to consider in light of discontinuation of limited monthly advanced actions in lower-priced subscriptions.
For context, I have a Professional plan, and having 30 Business actions available to me every month was the perfect amount to help deal with occasional specific email communications, but not something I would need for every message I send, thus not justifying the steep price of the Business plan.
A few times, during particularly busy periods at work, I would run out of actions towards the end of the month, and that would have been a perfect occasion for me to buy an "action pack" as a one-time purchase to deal with a specific need. I suggested this as an idea when I first started using the service, but it didn't come to fruition – perhaps now is a good time to revisit it.
As for the "customer confusion" issue cited as the reason for the discontinuation of the current system, presumably customers who go out of their way to specifically make a purchase of a pack of business actions would know what and they are doing and for what purpose.