I nipped in the Admiralty on Trafalgar Sq last Saturday lunchtime for a swift one, expecting to get royally horsed for being in a) London, b) in a tourist hotspot, and c) generally daring to have a pint outside of my own home.
£6.50. I wasn't even mad. I thought it was even cheap given the above factors, even if it was Amstel.
In my local though, £4.10 for a pint of best or something similar.
Offtopic: I ordered two large blonde lattes at the local Starbucks, and it was £10.10. it's literally cheaper to go on the piss than drink average-but-decent coffee now.