Maybe think about flying Southwest. Currently, their advance purchase fares are $63 off peak days and $73 peak days, and they frequently have specials, but, on the occasion that you have last minute changes to your plans or needs, you'll never lose a penny since there are NO penalties when you cancel their tickets. The full amounts you pay are good for a year from the date of original purchase. Also, there appears to be 10 flights a day in each direction, so there's a good selection of flights.