I think the establishment should be allowed to set any price they want. If you don't like it, don't go there. If guys stop going, there won't be a point of a ladies night anyway. But to claim it isn't sexist is ridiculous. You're making people pay a different amount based on gender; it's basically the definition of sexism.

meg:
Your argument doesn't hold water. What about the guy on the lower end of the bell curve of salary based on comparable skill and education level? He probably makes less than you (the guy with the lowest salary compared to a woman with average salary). Should he get cheaper drinks too?