Q: Perhaps you can explain this anomaly to me: I wanted to buy a ticket to Cali, Columbia from Boston. I was quoted a fare of $1034 roundtrip. But then I discovered that the fare from Boston to Miami was $234 round trip and then the fare from Miami to Cali was $381 roundtrip. The airline rep at Continental said I had to buy a through ticket and couldn't split the fare. Why not?

A: It's maddening and confusing, but sometimes it's cheaper to buy a "split fare" like this rather than a single through ticket. The only way you can tell is by pricing the seats separately. This is something a clever travel agent would have figured out for you. Too bad so many of them have been put out of business by the Internet. There's absolutely no reason why you can't buy two separate fares and save a bundle. Just make sure there's plenty of time to make the connection in Miami, and realize that there may be different rules for checked baggage (international rules may be more stringent than domestic). Also, should you miss your connection for whatever reason in Miami, the airline will be far less sympathetic than had you bought a single fare.

We did this several years ago when we flew from SFO to S. Africa. We saved over $1k between the 2 of us. One leg SFO to AMS, other leg from AMS to Harare, Zimbabwe. Tickets via KLM.

Didn't it used to be true that you had to use all the portions of a ticket, not just the ones you bought the ticket for? And that if you didn't use (say) the first part, they wouldn't let you use the second part? Are you saying this has changed?

Joel - read the question again. It refers to using the whole ticket and just paying separately for each segment. What you are talking about is delt with in the "Do I have to use my entire ticket" section of the blog and you are correct about that issue. I hope this clarifies what we are talking about.