If you have -- or can acquire -- the Amex Platinum card, you would likely save a few hundred dollars per ticket through the Amex International Airline Program; and you could use your Amex MR points to offset some of the cost of the cash tickets.

The sign-up bonus for the Amex Platinum varies, but can be as high as 150,000 MR points. Sometimes, you will get a higher bonus offer by visiting the application page more than once in a day.