I gave this a shot today. You have to go to www.americanexpress.com/travel (the normal "Chat" from your account page isn't the right spot). Considering it took about 20 minutes from "Welcome" to price, it's a nice ability to do that by chat instead of on the phone. If I provided specific flight numbers it might be quicker? I don't know.

I was quoted $2704 for a KL flight that ITA Matrix shows as $3049, by the way.