For those who are convinced that an instructor costing £150ph is going to give you better training than one which is “almost” free I would reminded you of Gliding. From 1984 to 1991 I few gliders and was instructed by enthusiast instructors who were mostly very good indeed.
Another example of very high quality instruction for not much money would be the LAA coaching system, which again, generally provides very experienced and knowledgeable enthusiast instructors.
There are many different ways one can take to get a “PPL” in the UK and I would not think the cost of the licence would have a significant impact on the quality of the resulting pilot, in most cases. The best way to spend money is to go to the most expensive school in the area and fly once a month, you may never pass, but boy will you pay pay pay. The lest expensive option is to shop around, learn all the different approaches, try a few trial lessons and then do the training as intensively as possible in a location and at a time of year when you are least likely to get weather interruptions. Having got the licences, then you can start learning to fly in the real world, take it nice and slow and try to find a suitable mentor.
Rod1