I always look for a nice hotel with breakfast in London. Then we snack easy during the day and find a decent place for dinner. We stayed last time at a HI Express Earls Court (new hotel with a very nice AC system) and around the corner they served a supper buffet for GBP 12.99 at the Ibis. Big salad bar, veggies and 2 meats with dessert. Got a discount card for the sightseeing so it wasn't so bad. The lousy exchange rate makes you look harder for bargains, but they are out there to cut your costs down.