The next time you’re planning an airline trip, common sense might suggest you buy a round-trip ticket.

You might want to rethink that, especially for domestic flights. In many cases, buying two one-way tickets might actually cost less.

Not only can you save money, but you’ll also have greater flexibility if you need to cancel the return trip, since the fare is then calculated as a simple one-way ticket.

If it’s a round-trip ticket, the danger is that both directions get repriced, and you’ll end up paying much more. One caution: This applies to domestic coach tickets, and not basic economy tickets.