i would pay $2/month at most for facebook.
It is an interesting thought experiment, though, to consider what facebook would look like if its revenue was derived from convincing users that it was worth a monthly subscription.
I compare that with Twitter at the time had two thousand employees. It makes no sense to me.
I topped up my FB balance with like $2 or $5 dollars, in ?2006?. When Facebook (quickly) discontinued that silliness, my account silently disappeared. MARK ZUCKERBERG, YOU OWE ME MONEY!
Which is bonkers to me personally considering how little I use it.