I said this below, but it has merit, so I'm posting it again. They took out the existing sell mat for marks plus rep for a very simple reason: exploitation. Keeping both exchanges, as they are, can be exploited in that players could buy mats, then sell them [i]and gain Crucible Rep.[/i] You could, essentially, buy as much crucible rep as you could afford. If they dropped the rep gain, I'd see no issue with it.