Another thing to consider is travel date(s). Last Fall we had requested a specific non-stop Delta flight from Atlanta to Athens. There was a $1000 up charge per person to fly 2 days prior to boarding. Just on a whim, I asked what the up charge would be to fly in a day earlier. Same flight, no up charge. We made reservation for the extra night for a fraction of the $2000+. Never hurts to ask, and be a little flexible with travel dates.