There is an old saying, you get what to pay for, in other words often the quality is reflected in the price paid. This is not to say bargains shouldn’t be sourced, but when it comes to life skill training you should be looking for quality training, and this normally comes at a cost. And when your training for such a life skill, is more than steering and parking,
Do your research to see what the driving school is offering, are they qualified, registered, and are they Keys2drive accredited. Do they use newer model cars, and how to do they present. Look at their website, how much information does it give you, is it professionally put together.
If your not sure have a single lesson with the driving school and then ask your teenager how they felt. If they are not sure try some else, not all driver trainers are reputable, some can come across as rough is good enough.
Also does the driver trainer give feedback, do they have an assessment sheet on your teenager, so they can track progress.
Remember the better the training the safer your teenager should be, if they take on board the tips that their driver trainer gives them along the way. Remember it’s got about getting a drivers licence, it’s about being safe on the road for life.