i suggest that you decide what price you would be comfortable with & buy if it's available....i wouldn't wait beyond the 1st week of march unless you like to gamble....however, some times good fares appear 4-7 days before flight time tho usually on domestic......good luck...

edit to add.....you are going during the easter period which might have a lot of travel......you could look a few days in each direction for cheaper flights.....or buy a fully refundable fare and hope you can find the cheaper flight and get your money back...