The best fare is between New York (JFK or Newark) and Istanbul for only $569. Aside from the Istanbul deal, other fares from most US gateways range between $800 and $1000, with east coast fares being on the lower end of this range.
As far as travel windows are concerned, departures must take place between October 26, 2014 and March 19, 2015 and return travel must take place between November 2, 2014 and June 19, 2015. These fares ARE NOT VALID between December 16, 2014 and January 6, 2015.
As you search for your flights, you’ll see that Lufthansa, Swiss, Austrian, Air Canada, Brussels and United Airlines are all part of the fare sale so your flights may be operated by any one of these carriers.
Keep this in mind as you pick your flights since the miles you earn for your Frequent Flyer Program will vary widely based on which airline is operating your flight!