Originally Posted by
milepig
If the open jaw doesn't price out well, the other option is to book a RT from IDA to either ATH or IST and to then buy a second ticket for ATH-IST or vice-versa.
Oddly, this doesn't price as well as a basic open-jaw.
12 September outbound, 22 September return:
IAD-ATH RT $792
IAD-IST RT $891
ATH-IST OW: $140
12 September IAD-ATH + 22 September IST-IAD is $754. Go figure.
It sounds like the OP may have land-transit or cruise plans ATH-IST anyway.