LOS ANGELES (KABC) -- The high cost of housing in Los Angeles is no secret, but listen to this: Entry-level schoolteachers here would have to spend more than 85 percent of their income on a median-level rental.That's according to the online real estate database company Zillow.L.A. may be extreme but it is not alone.Zillow says teachers just starting out cannot afford the typical rent in 49 of the 50 biggest U.S. cities.San Francisco is even worse: typical rent there is more than the entire starting salary for a teacher.