The Little Girl
The Cook skill was one of the most common and weak, as it does not help the person in combat or something like that. She can only cook delicious foods and on rare occasions, the food can permanently increase some attributes.
To increase the chances of food giving special attributes, the level of the cooking ability needs to be much higher. Or have a rarer cooking skill as a Master Cook, Chef, and more.
Since Lisette's skill was the most basic and common, Cook. She could create delicious foods, but it was difficult to have special attributes.
Liu Yang knows this, and yet, he bought her to be part of his group. At the same time, he knows that slaves with the best skills have already been bought by other nobles.
Who wouldn't want to have extra status permanently? Anyone would want something that easy. Besides, as the best skills were more likely, these slaves were very disputed.