That's no real increase and just fair. At the moment servers in the UK were cheap compared to paying in Eur (if you can pay in both). Although I don't really understand why they price in £ anyway. They could just base it on € and convert the other currencies every month. With the current weak € this would be nice for nearly everyone else.
AWS accounts for everything in dollars, and at the top of the monthly payslip there will be (only) one big number in your selected currency (which is just the total dollar amount at that day's exchange rate).
