That's not a group of people who exist in STL. Even an entry level teacher with a bachelor's degree is going to be clearing $20+ per hour with full benefits on top of that. For perspective, the paras make close to $15 an hour in a lot of districts and there's a huge gap in pay between a para and a new teacher.
I think $15 is too high for St. Louis, though.
Wife taught at Mehlville. South County, unless they make more in the inner city she did not make more than $20 an hour.
Teacher pay in Mehlville starts at over $36,000. That's over $20/hr. And that ignores benefits.
I agree $15 is too high, FWIW, for St. Louis, let alone rural MO. $9-$10 is more reasonable in St. Louis.