FWIW
Other London fares: $298 from Washington/Dulles or Baltimore-Washington; $328 from Chicago; $358 from Houston or Dallas; and $378 from Florida and California gateways.
There are some good perks, too. Travel dates can be changed before departing without penalty. There are cheap ($250 per flight) upgrades available for World Traveller Plus, BA's roomier super-coach cabin.
And pax save an additional $10 off fares when booking at the BA website.
Travel is valid between October 23 and March 31 and the lowest fares are available on Monday, Tuesday and Wednesday. Tickets must be purchased by October 28.