There are also travel agencies located in ethnic areas of the city you live in that cater to the locals traveling to/from the Mother Country. I don't know where you live but let's assume, New York. Want to go to Athens? Find a TA in Queens. They have such a huge business that they buy blocks of tickets to Greece and offer them to their clients. Friend got a ticket to Athens over the summer for $600 on Iberia.
They also get great biz fares as well.
You will find a lot of consolidators in Hispanic Areas, they have incredible deals to Mexico, Central & So. America. Going to Europe? Try and find a TA in Canada. Flying out of SE Asia? I use greentravel2000.com (hotels too).