I was looking at Sabre Dot/Res for cheapest TK fares from JFK to DEL via SAW (Instanbul). It indicates for dates in question (departure in Feb and arrival in Mar) that cheapest base fare is about $505 (CAN) - G fare basis. Your Galileo and Sabre ITN fare availability functionalities indicate that there are plenty of G fare seats available on all 4 flights, for the any pair of dates we are interested in.

However, the TK web site (US) indicates that the cheapest fare (including taxes and fees) is over US$1600. Can you explain this discrepancy?