Ascend Charlie did in fact say 45 grand for a PPL, whatever he might have meant.
As an instructor, I quote that £12,000 to my students. But £18,000 could easily be closer in reality. Let's have a look at the figures.
Hourly rate: £210 plus VAT and landing fees where I am. You can get it for a bit more or a bit less, but I think that's probably typical. If it's a lot less do some research; in my experience you get what you pay for...and I learned that the hard way.
OK, so around £250/hr all-in. Minimum required is 45 hours, but most people take 60-70. Since Charlie is young and plans to do it over a relatively short time, let's say 50 hours, though this may be over-optimistic. That gives £12,500 (which is where I got my figures from). Of course, he might do it in minimum hours, which would mean it'll cost around £11,000. BUT...books, charts etc - probably another couple of hundred quid. Ground school - usually learn it by yourself, but some places teach it, and would cost a bit. Exams - can't remember what they cost, but not free. Medicals and so on.... So perhaps £14,000 would be more accurate, as an average. Though for plenty of people Whirlygig's figure is probably closer.
As for our pay, £30-40 per flying hour is hardly a fortune. Briefings are free, and in most places tend to be thorough. With the UK weather, instructors still find it hard to survive. But unlike f/w instructors, who are paid less, it is just possible to make a living out of it. So they tend to be career instructors, rather than the airline wannabe hourbuilders and retired folk you get in the f/w world. As such, I'd say the overall standard is better...and I've been a student in both.
Anyway, even if you paid the instructors less, say, £20 an hour, it would make little difference. Students would pay about £230/hr, and the whole course, for 50 hours (to save my maths!) would be £1000 less. So you'd save a grand, and have instructors who cut corners since they probably weren't making enough to cover expenses! Not a lot of point really.
Flying is so expensive in the UK because of the cost of fuel in particular, then there's land prices, CAA fees, etc etc etc. Don't blame it on the instructors.