Not all university students are equally costly. You write: "The diagnosis of higher education is different because it costs about educating a student at university costs about 200 times what it costs at the primary level. "
An English or even economics student costs far less to educate than someone in natural sciences or experimental physics. There are VERY costly equipments and laboratories. The English major just needs some pencils and paper... The English professors are in abundant supply compared to the ones in sciences, so they have lower salaries.