Consider an approach of: "I have a budget of XX a month, for the next umpteen years". If it is enough, go flying. At some point, with dedication, you'll have a PPL, and the only difference you'll notice will be that you can then take passengers to share your passion. Otherwise, you're still out flying!
Absolutely excellent advice. Never seen it quite phrased this way, but it sums it up perfectly.
Far too many people sign up for intensive courses, thinking they can just bash the licence out in a month or so as a milestone and then move on, but in the UK at least it rarely works out. The weather gets in the way, you don't progress quite as quickly as you'd hoped, or you can get your act together and get all the exams done in time.
If you see it as I can afford to spend X a month on flying for the forseeable future, and you're able to take say 2 or 3 lessons a month, you'll progress well and then still be able to afford flying after the course. Again, lots of people get in to this with unrealistic ideas of what having a licence will be like. Weather can cancel a planned trip, and hiring an aircraft from a flying school can be expensive and awkward, so the fact is you just end up flying to a random airfield, eating some bacon, then flying home with ultimately not a lot achieved at the end of it.
If you're seriously able to budget for a decent share in a decent aircraft and the ongoing costs that it involves then you'll have more chance of making good use of the PPL. If you're currently wondering whether you can afford the extra £4k that has been queried, I'd certainly think again about starting the course.