Broadcast economics: the subscription is the small number
A WhatsApp campaign programme has three cost drivers and only one of them appears on the platform price list. The subscription buys the console. Meta bills the conversations, priced by category and country. And the replies your campaign creates need people to answer them. Budget only the first and the programme will cost several times what was approved.
Work forward from the campaign plan
Decide how many campaigns you will send each month and to how many people, then project list growth over twelve months. Multiply out. That gives marketing conversation volume, which is the number that actually drives spend. Add your routine utility and service conversations, and only then look at rate cards.