I'd pay $12 per year for ad free Facebook.
https://www.statista.com/statistics/251328/facebooks-average...
($53 per US user)
Now, whether asking users to pay for a social network at all is a viable business model, is another question.
If you are seriously considering paying for the poison that is Facebook, might I recommend you delete your Facebook account instead, and give your money to someone that needs it?