In June 2017, the American Express International Airline Program changed to a discount program, rather than "buy one get one free".
https://www.americanexpress.com/us/t...ram/index.html

To research and book, you can
1) Call Platinum Travel Services (1-800-525-3355) or Business Platinum Travel Services (1-800-553-9497). $39 booking and change fees apply
2) As of October 18, 2018, customers can use Live Chat to receive quotes. Log into your account at www.americanexpress.com/travel
3) As of May 2019, customers can log into www.amextravel.com and search and book some IAP fares. Not all carriers participate in online bookings, and not all fares appear online. (Relevant FlyerTalk thread 1 Relevant Thread 2)

The program is available on International First, Business and Premium Economy Class tickets booked through American Express Travel, on both refundable and non-refundable fares.
Good for purchases of 1 to 8 tickets on participating airlines.
Use Pay with Points for all or part of you fares, plus you still get miles from the airline.
Subject to $39 servicing fee per ticket for Platinum card members when calling.

"Travel must originate in and return to U.S. gateway (may exclude certain overseas territories) and select Canadian gateways. One-way travel permitted on some airlines where routing originates in U.S. or select Canadian Gateways." Known to include YVR, YYZ.

It was suggested that a Wikipost be written to try and collect past and example discounts, as the fares themselves are unpublished. The discounts vary, sometimes widely, based on availability, fares, and sales. I've broken it down into ranges, and sorted by the number of reports. I also combined AF/KL/DL as they have joint ventures TATL so it's hard to say from all posts which metal members were reporting. My calculations for discount ranges do not intentionally include the $39 booking fee.

Delta / Air France / KLM