If you live in US, the number has to be probably close to $30/month to match what FB is making out of you
Is it per year? Per Quarter? Not clear to me.
But yeah, definitely not per month, but also much higher than the $1/year the GP is offering.
1: https://www.statista.com/statistics/223280/facebooks-quarter... 2: https://www.statista.com/statistics/408971/number-of-us-face... + ~20 for canada