You missed your opportunity to make vast amounts of gold, farming up w/e to sell to people in the first few days of release... people would pay through their nose to get realm firsts - easily make 30-50k in a day.
Buying 'old' [Cata] mats, cloth, dirt cheap when people were clearing their bags and banks... prices went up dramatically due to countless monks being made, for their professions. e.g. - Embersilk cloth were going for like 3-4g a stack - now they're going for 80g. Massive profit from just that.
etc.
You need to think of things in advance