BrodyStone21
As @RelicSystem suggested, although it's a bit more complicated.
Basically:
Create a [Classifieds] user group.
Create a [Classifieds] tag.
(a) set [Classifieds -tag] with:
-i)'Start discussions',
-ii)'Start discussions without approval' permissions both enabled for the [Classifieds -user group].
Set-up 'User Badges' extension.
(a)create a [Classifieds] badge.
Set-up 'Auto Moderator' extension.
(a) create an Award [Classifieds -badge] criterion.
-i) setting the [Classifieds -badge] award requisite metrics as the minimum number of posts needed for entry into the [Classifieds -user group].
-ii) setting the [Classifieds -badge] award gain action to auto-move member to the [Classifieds - user group]
🤔...and I think that should just about do the trick.
(*though I could be mistaken)