Didn't find this so here we go:
Most tailors are lazy. They do not use their 4 day cooldowns every time they are up. I am well liked in my guild so I looked up on our website who was a tailor, and sent a mail/message to each of them requesting to use their Shadow/moon/spell cloth CD if I provided mats. 90% of them accepted it.
This means you get 2 cloths just for the mats, which are either around 40-45g on my server, or easily farmable in <30 minutes. Shadowcloth is the cheapest selling one on our server and I make 70g off each persons cooldown with it, coming to a 25g profit for no real work at all if I buy the mats.