A single per-platform price comparison hides the factor that actually drives your bill. A worked 1,000-invoice-a-month example run through both platforms’ real published rates.
Overage detection can lag five or more days with zero warning. Here’s Microsoft’s exact end-of-credits calendar, the fallback order, and what to provision before the seeded allowance disappears.
The most expensive of three model tiers is the one every new AI by Zapier step starts on. What each tier actually does, and the habit that stops a simple prompt from quietly billing at 5x.
400 activities a month sounds generous until you learn every knowledge lookup, search and action counts separately. The exact limits by plan, and how fast a single run burns through them.
Most guides answer which tool. The question that decides whether an automation survives is which task. Here is how to score candidates, what to start with, and what to leave alone.