The term average is being misused here, when really they just had a small sample size that doesn't reflect the general population. I'm a UK citizen and most people spend less then a tenner for a bottle of alcohol unless it's a special occasion and something like Gordon's gin, Jack Daniels, etc. You only have to look at what people buy in store to see the cheap stuff sells the most. Most corner shops won't even stock the pricey stuff and would rather stock the shelves with teenager cheap White Lightning instead.
Concert tickets going for north of a hundred per person only seems to apply to the biggest names and being fussy with seating. Isn't £30 more like the rates charged to see Ed Sheeran and Adele, maybe Slipknot? £100/$100 would be balcony views and stuff surely? Smaller artists tend to be less then £20 with travel and food costing more then the concert ticket. I haven't checked prices in ages though, but I'm aware skalpers whack them up to over double what they initially paid. £100/$100 seems like the price for a two day festival.