"About that, I have checked and seen that the experience needed to reach the next level, is quite high. I don't think I can level as fast as before unless I use the pills you told me not to".
The experience that Yang Chen needed to reach the next level was so high that he reckoned he would have to besiege another clan like the Zhang clan to go through a level up.
This problem could be easily mitigated if he used the Experience Points Booster he got from the second started box that could be opened once one reached the battle master level.
However, Amon told him that it was a waste to use it right now. As such, the two experience booster points that he got from the first and second started boxes, were still sitting in his inventory.