Do I overpay my babysitter, or are my friends just cheap?

I have 3 kids, ages 6, 3, and 16 months. I pay 12 dollars per hour: 5 for the youngest, 4 for the middle child, and 3 for the oldest, based on self sufficiency. I only use sitters that have first aid and cpr certifications, and come with good references that I have checked. I realize this is more than teenagers usually make, but I want to draw quality babysitters. My friends say they would never pay that, and if I continue, then babysitters might start requiring that from them. Should I really reconsider my pay? or are they being ridiculous? I only use a babysitter (generally the same one who has 9 brothers and sisters, and really needs the money) once every month or so.