"I am going to do a search for kitty groups and maybe I can join one for free. Why should I have to pay for XYZ Kitty group when there are others with probably many of the same members that I can join without paying anything."
To me, the alternative (Mark's Pricing Changes alone) does not seem preferable:
"I am going to do a search for kitty groups and maybe I can join one. Why should I have to wait around to see if XYZ Kitty group ever has an opening when there are others with probably many of the same members that I can join that aren't full."
At least with this Proposal the would-be member has the option.
