I'd dispute that folk festivals are charging outrageous prices but I am curious to be honest, how exactly do you expect festivals to cover their costs by charging 'bargain' prices?

In terms of venues, tis true some may charge over the top prices (I'm aware of a venue/event in Leicestershire charging £25 a piece for known names on the folk circuit who charge around half that elsewhere, that would and does exclude people) but for the most part these are businesses with their own costs, overheads and staff to be paid so again its all very well you suggesting a bargain price but in the real world... (and leaving aside the question of whether an artist wants to be able to afford to eat)