B****y hell Debih Mind you, we've been to hotels (parties, wedding receptions,etc) where it's been similar. You need prior warning, then you can have miniatures about your person so you can just order coke, or - ahem - even a whole bag from a wine box in your handbag
A certain person from old DM days introduced a lot of us to that particular trick Molly If you know you're going to an expensive venue then really, ingenuity is your best friend
I paid £15 for a bottle of wine in the pub the other week - how does that compare with other parts of the country? I know I'd pay much, much more in London.
I did pay around £7 for two plastic cups of water at Shepherds Bush Empire last Summer but really, I expect to have to pay over the odds in London.