I see the 200 post count before sales as completely fair for all the rational reasons...
hell, I founded & admin'd a forum for disgruntled jazz musicians back between 2005 - 2012 and new members got the boot if they didn't post an introduction with a minimum of 800 words, no typos and balls accurate punctuation (it was in the rules when you created an account)... it was meant as much as a smartass thing as a real world way of forcing folks to share & engage.
That said, I also enacted a feature called "Ban of The Week" whereupon I would randomly ban a long time, overly-serious and heavily contributing, member and set their privileges to not being able to post or see any other parts of the forum except a thread specifically created about them: where everyone else at the forum would brutalize them over their personality/playing abilities/personal photos/etc. After their seven day ban was lifted the thread would become a Sticky in the "Ban of The Week" sub-forum... only the rarest breed could take the humiliation (I received some of the most verbally heated emails from whatever poor bastard was chosen ~ and deservedly so... I was much more of a dickhead back then than now).
In the end though most couldn't handle that level of engagement or shit-talking, and we went from nearly three thousand members to just 15 people... and it was dumb to keep paying the bills on that so I created a Facebook Group for the depleted flock.
Anyway, OF has very reasonable rules to my mind.