Festivals in mainland European cities are usually free to all punters, paid for by local councils as a service to their electorate.
This is because the arts (tradarts or not) are properly funded, unlike here.
Those I've been at book whoever's good and who people say they want.
There's be no turned up noses at the Waterboys or Solomon Burke.
I once saw Genesis (OK, I didn't really want to) with the Dransfields as support in Paris.
And BAP, Juliette Greco and Gilles Vigneault at the Loreleifelsen on the Mosel.
Now that Led Zeppelin has reformed I hope an English festival books them as I understand tickets for their comeback concert are £145.