I don't know about USA, Bebe, but here in Australia, relief teachers are not treated so well. It doesn't matter what your experience is, or how much certification you have, you are stillp aid on the bottom rung of the ladder. I did some relief at a school where I spent many happy years of teaching. I got a call one morning just after nine. I got ready quickly and was at work by 9.45. I got paid for half day's work. I never went back.