The copper membership allows those users to have an avatar. It should be a feature who come with the rising price of that membership. 0.0065 BTC isn't a bad price at all, but maybe the CM thread should be updated because it doesn't mention the Avatar.
https://bitcointalk.org/index.php?action=credit;promote Copper - 0.00675676 BTC: Allows you to post images even if you are a newbie, reduces the time-between-actions limit, and provides some of the same benefits as being of natural Member rank.