How to set an appropriate auction price?

For photographers, it is obviously unrealistic for them to spend hundreds of dollars to ask a model to take pictures, usually just to learn photography or practice creation, for non-commercial purposes. Therefore, they can reduce their financial burden by making an appointment, and at the same time, they can exchange and learn with more photographers. With the development and trend of contract auction, with the increasing number of plane models, it is difficult for brokerage companies to arrange jobs for each model, but the contract stipulates that models are not allowed to take jobs without permission, which is cruel and selfish. Even if there are activities, the commission is inexhaustible. The contract auction is to let the girl who is a plane model make her own decision.