How free is that complimentary ticket?

Last fall, my wife Sari responded to a promotional offer from American Express Publishing for a trial subscription to its monthly magazine Travel and Leisure, lured partially by the offer of a "free companion air ticket" for a domestic flight.

We received a response card to complete and send back for our "complimentary companion certificate," which we did. In due course, an "activated" voucher arrived, which included a statement of terms and conditions.

The transferable coupon entitled us to book one adult, round-trip, coach-class airline ticket to more than 100 cities in the lower 48 states. The cities were divided into seven geographic zones, and the fare for a given trip depended on the zone combination for the departure and destination cities. Fares on the resulting chart ranged from $210 to $575, although as the terms noted in certain circumstances the "pricing provided may be higher than the fares stated."

In any case, the base fare on the companion ticket was to be free, though both tickets were subject to the same required taxes and fees. Tickets must be purchased at least 14 days prior to departure and booked either through www.companionbooking.com or by calling the toll-free number. Actual routing would depend on the selection of airlines involved with the program at the given airports.

So far, so good. We have until the end of June 2008 to complete our trip, so we put the voucher aside to wait for a good opportunity.

We're still looking.

The first possibility was a trip to Boston my wife wanted to take with her mother. According to the Companion Booking chart, the first person fare for that trip should have been $335, and it was, but adding taxes and fees, the total price for two using nonstop US Airways flights that departed at 8:55 p.m. and 6 a.m. was $398.

The deal seemed reasonable, but the departure times were not, so she checked the cost of two tickets booked directly on the US Airways Web site. The total price for the same departures was $185 each or $390 for two, and she found two seats on nonstops departing at more desirable hours at that price and booked them. She was the first to sneer at the value of the Companion Booking voucher.

A similar calculation unfolded several weeks later when I wanted to fly to Myrtle Beach, S.C., with my son Ben. That trip would be within Zone 2 on the Companion Booking fare chart for $345. Sure enough, my query was answered with a selection of routings all on Delta flights through Atlanta. But a note at the top of the page advised that the price had changed and the base fare was actually $377.68. With taxes and fees -- $51.26 per person -- our two tickets would total $480.20.

A new carrier, Myrtle Beach Direct, was advertising nonstop trips from Pittsburgh for $99 each way, or $488.60 round trip for two, but they had no flights on the days we wanted.

So I went to the US Airways Web site and found reasonably efficient round-trip connections through Charlotte for a total of $480.20 for two, the exact same figure Companion Booking was quoting for my two-for-one deal! Where were the savings? I booked that trip directly with US Airways, and we enjoyed four flawless flights.

My third attempt to cash in on the Companion Booking deal was for a possible trip to Phoenix in May, a trip from Zone 2 to Zone 5. The chart says the base fare is $520, and with a special bonus, Companion Booking offered two round trips for $593.98, using a five-hour Southwest nonstop one way and a 13-hour Continental connection through Houston on the return.

That fare compares favorably with $651.60 for two on Southwest nonstop, but it's certainly nothing like a two-for-one savings. The ratio is better against the $963.60 US Airway wants to fly us nonstop, but Companion Booking is nearly 20 percent more expensive than the convenient connecting flights Continental is offering through Houston ($503.18 for two)!

Now, price isn't the only factor that comes into consideration, and I'm still deciding which option to take on that May trip. But now I won't automatically assume that a two-for-one deal is the best deal to be found. And neither should you.

This is not to cast aspersions on Companion Booking. The firm has responded appropriately according to the stipulations mentioned in its offer. But you have to wonder about the value of any two-for-one ticket deal that winds up costing as much or more than two tickets purchased separately.

Oh, and regarding our subscription to Travel and Leisure, we've decided not to renew.