I don’t know about CheapTickets specifically, most online travel sites (agencies) will charge you a cancel/change fee (sometimes nothing, but sometimes over $100) and they have strict restrictions on how many days prior to departure that you can cancel/change. But that is not all. Then, you need to pay the airline their own change/cancel fee. This is at least $100, but I’ve seen $400. Finally, they will charge you for any increase in fare (of course). You may save on some of these fees by not booking with an online travel agency (ie. Cheaptickets, Orbitz, Expedia) and book your tickets directly with the airline (ie. Delta, United). Hope that helps! Good luck.