I was a wheelchair pusher for a summer back in college at a hub. The average seemed to be about $2-3 that'd I get. I was pretty happy with $5. Sometime I got nothing. Sometimes I got $20 or more. If they ask to take you to the bathroom or stop to get food and help you make your connection or anything like that, consider that. They make minimum wage plus tips. It was fun to be around airplanes and the airport, but it's not something I could do again.