The thing with fares is, they change frequently. Subscribe to a service that watches the fares for you if you have to buy your own. Depending on market and competition, fares can drastically get lower as you get closer to the travel date and some planes have lots of seats to sell. Since my business buys my seats, I don't have this worry. For personal flights, it depends on how locked in I am to certain travel dates. I usually book mileage tickets for personal travel and watch the fares as well. I can redeposit the mileage if need be.