I negotiated my wage and got a decent one. But it comes with a price. When you negotiate as a woman, you are perceived as difficult. And even with the right qualifications and skills they value you less. You need to be way better to be perceived as worth it. Man can just be "average" and sometimes are offered waves on potential, not actual skill. So it is not just negotiation, it is also perception of value. For example, if Mary wanted 75k, she should add tha "it us market value". Otherwise, the offer would be lower anyway.