Base fare is one of the biggest scams currently being run by airlines.. The big '20% off Sale' applies to base fare only, etc etc.
Look at London to Vancouver on October 11.. base fare is $2! A 20% discount on this flight would save you 40 cents!
Air Transportation Charges (ATC)$167.18
Adult - Base fare x 1
$2.00
Other ATC
$165.18
Taxes, fees and charges$154.90
Air Passenger Duty (APD) United Kingdom
$128.84
Passenger Service Charge United Kingdom
$26.06
Total
322.08 CAD
Ron.