What part of May are you looking to travel and between which airports?
Do you have a preferred airline that you are looking to travel on or are you willing to fly on any airline?
Are you flexible with travel times or do you need a flight around a specific time?
What is an affordable round trip airfare for you with taxes and fees? What do you consider "crazy" as far as airfare goes?
We usually travel in mid-May from PWM (Portland Maine) to MCO. I usually buy our airfare in January or February once AirTran and/or Jet Blue starts with their late Spring/early Summer sales. If I watch I can usually get the trip round trip for $200-$250 dollars.
I have found that it is cheaper if we travel mid-week rather than over the weekends. Fares on weekends to MCO tends to be higher especially on Sundays. We can usually snag the cheapest airfare by going on Tuesday, Wednesday, and sometimes on Saturday.