http://www.bbc.co.uk/sport/0/football/29622950To be fair it makes no comments about why teams charge what they do, but if it was to do so I'd hope that they approached non league prices with a fair viewpoint.
All this does for me is highlight, once again, that media revenues and the like are unevenly distributed across the football pyramid.
Of course Manchester City, Barcelona and Real Madrid can charge less than FC Halifax's £18 per adult. Match tickets are nowhere near Manchester City's biggest method of income, while for most (if not all) non league clubs there is a heavy reliance on the same hardy souls turning up and paying their £10-£20 on a weekly basis. If Conference sides charged an entry free relative to the standard of football it would be completely unsustainable, not every football club has a bottomless pit of money.