What you need do to advance to the next level of crafting profession

There are totally five levels, Lesser, Regular, Greater, Expert, and Master. You are only allowed to master two crafting professions. You are required to pay 3,500 kinah to learn the first level. In order to reach the next level in your crafting professions, what you must do is to max out your experience bar in the current level. There are 99 points of experience to fill, once you have reached the max experience you must go to your profession skill trainer and pay him. Here is a specific example to illustrate this. At the very beginning of a crafting profession, you have 1/99 skill points. Once you have reach 99/99 skill points by crafting, in order to reach 100 skill points, you are required to pay 17,000 kinah to your trainer.