I'm leaving for the Big Island and Kauai next week, traveling with a British friend who has (until now) been taking care of all of our bookings. Her last e-mail to me said that she'd reserved cars with Avis on both islands, five days on the first and eight days on the second. The prices she quoted were a rather astonishing £192 and £216 for the two rentals--yes, that's pounds, not dollars. I flipped, immediately went to Orbitz's website, and booked Alamo cars for the two destinations for $117 and $248 respectively. Alamo was by far the cheapest of all the companies, but even Avis's rates were less than what my friend had contracted for. Interestingly, I checked Expedia's website and the prices quoted there were far higher than on Orbitz (Alamo and National were not even listed).

My question is: is there some sinister reason why Alamo (via Orbitz) is so much cheaper--bad service, hidden fees, tendency to lose reservations, or anything like that? Are we going to show up and have no car, or get slammed with some unforeseen charges? I have rented cars from Alamo before with no problems whatsoever, but I've never used Orbitz to book a car before. Did I just make some fatal error?