Do you use alerts on websites like Kayak to see when a fare drops? If you receive an alert, what do you do next?
Check out all the details of that fare. Does it include all extra fees? Does it fly at a time that works for you or do you have to fly at a strange time? Is it refundable or do you pay a huge fee? Are there blackout dates or dates with higher fares?
Read everything. Then, check other sites, especially the airline's site. You may find a better deal.