I just paid $2.60/gallon for 91 Octane Chevron two days ago.
Now of course, London has a MUCH better public transportation system (busses, Underground) than California has even though California has one of the best public transport systems in the USA. Most cities (for example, Miami/Ft.Laud) have practically non-existent public transport.
But still...$9/gallon, I'd move. Fast. Plus the weather sucks in London.