Actually, I don't see anything wrong with Artemis selling her excess tubes, or for that matter, anyone's excess stuff either. As long as they are selling at cost price (the price they bought) or lower, why does it matter? They are not earning anything at the expense of the forum, just clearing their overbought stuff.
So I don't understand why the rules are so strict. Worse, there's a mentality of a "witch hunt" going on in the forum. Mummies snitching on each other to the mods. You report me, I report you too. It's a very unhealthy attitude.
Just my 2 cents' worth.