You get what you pay for.... usually
No doubt there are "better" instructors at half the rate of some. The advise about interviewing the prospective instructor and requesting references (and following up to interview them) is the best advice.
All said, consider this. A flight school charging $30 for instructor time, how much is the instructor getting? Even if they are keeping the whole thing, they are earning an income at the rate of $30,000 annually
if they fly 1000 hours. Sure some put in more hours a year, but you get my point.
At $30 per hour, you are getting someone who is either doing it for a hobby/fun or is building time, looking for the door. Transit instructors are a facet of the industry but you run the risk that you will be trading out instructors while completing a long course (like an inst rating).
Is that good good for your training? Some times change is a good thing, many times not; but you can't predict nor control events when your teacher is looking for a better deal. At $30 an hour, just about any other job flying is a step up, just saying....
