Purely in terms of ticket prices etc (with booking fee). Not beer pennies, train fares and whatnot. I don't live in the UK now and more or less stopped going to gigs in about 2007 so I'm out of touch and can't remember.
What's the going rate for:
a) a toilet circuit band (typical venue: Camden Barfly),
b) A middling band (typical venue - University unions / typical stop-offs for the NME awards tour)
c) A relatively big hitter or overachiever (Tame Impala at Brixton Academy for example)
d) Arena show.
I realise I could easily look this up but I'd rather have first hand answers from your experience.