I don't know, but it's either a lot or the service is really expensive. They're wearing fitted uniforms. They don't hesitate at all, so it's clearly a well-practiced routine for them. They seem pretty healthy, happy and well-groomed, so their wages are at least decent, if not above the local average. In fact, it looks like they've had their hair and makeup done by a professional. That's not cheap. Furthermore, this is all being filmed in color in the 1930s. I don't have the numbers on hand, but I imagine thats the contemporary equivalent of filming in 70mm IMAX, not cheap. This is very obviously a big budget operation. For whatever reason, the demand for a salon that's specifically equipped to serve ambulatory scarecrows, tin men, anthropomorphic lions, and teenaged Kansas farm girls was extremely high in that particular time and place.