Some schools have “deposits” in their contracts. Some have various kinds of fines. I don’t know how prevalent it is, but it’s out there.
Maybe there are some good schools that have provisions like those, but in my opinion, if there’s a lot of that sort of thing in a contract, or if the fines are big, it’s a not a good sign.
I may be wrong in this assumption, but if a school provides for deposits, or big fines for leaving, I assume it means they’ve had problems, maybe serious problems, with teachers leaving in the past. And even if the teachers were wrong or irresponsible in leaving, even if it wasn’t the school’s fault that they left, a contract with heavy fines and/or deposits would make me suspect that the school had developed an adversarial attitude towards its teachers. Even if the attitude were justified by the school’s past experience, it wouldn’t be my kind of scene.
Out of something like desperation (real or imagined), I once signed with a school that had fairly hefty deposits in the contract. After a few weeks of enduring the bad vibes at that school, I got the thought, “Hell, I ain’t that desperate,” so I quit.