Andrew was not prepared to negotiate about the fashion show, so he was at a disadvantage throughout the negotiation. Candice being a woman of experience took advantage of this fact.
Regardless, Andrew was focused on earning certain benefits, and by his own account, he believes that he earned enough benefits. He didn't expect to make money from this, so he concentrated on other things.
He managed to obtain three benefits that he considered to be what he needed. The first was that the training would take place in the Heavenly Palace. That way he didn't have to let staff out of the establishment because they would waste more time, not to mention that Helena was practically the models' trainer, so when she left the courtesans would not receive their classes, which was not acceptable to Andrew.