I have the same ITIN booked out on both; both give different prices and fees for the same fares...
Fare 1: Carrier AC K14XR2TP YYC to LAX (rules)
Passenger type ADT, one-way fare, booking code K
Covers YYC-YVR (Economy), YVR-LAX (Economy) CA$106.50
Fare 2: Carrier AC K14XR2TP LAX to YOW (rules)
Passenger type ADT, one-way fare, booking code K
Covers LAX-YYZ (Economy), YYZ-YOW (Economy) CA$206.50
Canadian Goods and Services Tax (XG) CA$17.51
USDA APHIS Fee (XA) CA$5.10
US Immigration Fee (XY) CA$7.10
US Customs Fee (YC) CA$5.60
Calgary Airport Improvement Fee (SQ) CA$25.00
Canadian Air Travelers Security Charge (CA) CA$12.10
Toronto Airport Improvement Fee (SQ) CA$4.00
Canadian Harmonized Sales Tax (ON) (RC) CA$0.52
US September 11th Security Fee (AY) CA$2.50
US Passenger Facility Charge (XF) CA$4.60
Subtotal per passenger CA$397.03
Number of passengers x1
Total airfare & taxes CA$397.03
Passenger Type Adult
Flight 1 - Airfare (Tango Plus)
99.00
Flight 2 - Airfare (Tango Plus)
199.00
Surcharges NAV 15.00
Taxes, Fees and Charges
Canada Airport Improvement Fee SQ 29.00
U.S.A Transportation Tax US 17.04
U.S Agriculture Fee XA 5.10
Canada Goods and Services Tax (GST/HST #10009-2287 RT0001) XG 17.51
U.S Passenger Facility Charge XF 4.59
Canada Harmonized Sales Tax (GST/HST #10009-2287 RT0001) RC 0.52
U.S.A Immigration User Fee XY 7.14
Air Travellers Security Charge (ATSC) CA 12.10
September 11 Security Fee AY 2.55
U.S. Federal Customs Fee YC 5.61
Total airfare and taxes before options (per passenger) 414.16
Number of passengers 1
Grand Total - Canadian dollars $414.16 CAD
What gives?