It's been a while, 1996, since I was an instrucor in the US, so the pay might be slightly different. The amount you earn also depends on where you fly, if you get payed per hour or if you get a weekly/monthly salary.
I used to fly for a small fbo in northern NJ. I made $13/hour for PPL training and $15/hour for CPL or IR training.
On the average I made about $200/week. In the winter I made less, so I had to wash or polish airplanes to get money. In the summer I made more, with weeks between $350 and $400.
Next to flightinstructing I also flew for
trafficwatch, report traffic to a radiostation. There I made $9/hour.
Hope I answered your question.
BC