Actually, the * part of that is not clear. What does the * part apply to? And, reading it, it sounds like only supporters can post that they want to sell stuff unless a supporter posts they are looking to buy stuff, then a mere member can post that they've got that to sell. And what is the bit about the "30 day rule"? It sounds like it's referring to something mentioned earlier, but that's the first mention of it.
Because of this mysterious add-on at the end: