I understand limiting private messages for a temporary period. On a car audio site I was a moderator on what was done

When someone signed up they would be limited to X amount until they reached a certain amount of legitimate posts. Not post whoring. This was also used to allow them access to classifieds and other areas

Just an example not the exact amount. They'd go from 10 to 100 at that point. Making it easier to conduct business with others and vendors. Since some especially vendors may not want to have all prices within a thread

Then unlimited messages were available for paid members. Unless they were grandfathered in prior to the changes

Is this something that can be looked I to here? 5 messages is very difficult to work with