Originally Posted by
kop84
Plus LON, the base fare could be $3 and the ticket is already practically $1,000 with all the taxes further limiting B6's ability to drive fares down.
That's a bit of exaggeration that is unhelpful here. A $378 coach ticket BOS-LHR-BOS (sold by Delta, actually) has $228 in U.S., UK and London airport taxes and fees.
From ITA Matrix:
US International Departure Tax (US)$37.20
US September 11th Security Fee (AY)$5.60US
Passenger Facility Charge (XF)$4.50
United Kingdom Air Passenger Duty APD (GB)$102.40
United Kingdom Passenger Service Charge Departures (UB)$61.20
United States Immigration User Fee (XY)$7.00
United States Customs User Fee (YC)$5.77
United States APHIS Passenger Fee Passengers (XA)$3.96