I don't know how a cross-country plane ticket can cost less than $300.

Spring and fall are my busy travel seasons; I'm posting from Boston this afternoon, and between now and the beginning of June will be (God willing) in Washington, New York and Los Angeles as well as in Boston.

I'm making plans to attend the L.A. Times Festival of Books, which happens the last full weekend of April; The Mystery Bookstore puts up a big booth and invites dozens of authors to sign, and it's a great time every year.

It takes all day to get from Gardiner, ME to Los Angeles, CA, and getting home again usually requires an overnight flight. You can't fly directly from Portland to L.A.; you have to change somewhere, usually in Boston or New York. It's at least a two-plane journey.

So imagine my surprise to find plane fares as low as $231 online. Granted, that doesn't include tax, and I'd probably have to pay extra to check a bag, but that's still well under $300 to travel at least 3,000 miles (according to Google Maps, it's 3,084 miles to drive from Portland to L.A.). Math is not my strong point, but that is less than eight cents a mile.

I understand that these flights are scheduled anyway, and they need to fill the seats. I understand that some flights to and from Maine may be federally-subsidized. But still -- I'm torn between delight at traveling so cheaply and a real fear that this is simply not enough money to keep the plane in the air.

When I was a small child, it was a big deal to travel by air. My twin sister and I, flying to South Carolina to visit our grandfather, got dressed up, and were given not only full meals but stewardess pins (they were still stewardesses then) and decks of cards with the National Airlines logo.

These days I'm grateful to get half a can of diet soda, and flying in general is more like taking the bus used to be. (Paradoxically, taking the bus, as I just did from Portland to Boston, is now a genuine pleasure.)

While I'm glad for cheap airfare, I can't help but think that maybe the pendulum's swung too far. I'm willing to pay at least ten cents a mile.