''But if you look at it, we have had only 16 complaints in the last 12 months, which is minimal out of 150,000 passengers per year,'' Hering says. ``There are always going to be complaints when you talk about travel, because it's subjective. People don't read our terms and conditions.

``It says on our site, all auctions are not changeable or refundable. We don't give refunds. We don't guarantee that every date will be available. On airline seats, we don't guarantee every class of service.''

People want both a fabulous auction deal and total flexibility, he says, but that's not realistic.

Here are the main travel auction sites. If you're smart, you may find good deals:

• Luxury Link (www.luxurylink.com) is a for-profit Los Angeles-based travel agency that negotiates with high-end providers. Its website clearly states the retail value of the offer, lowest bid and any fees or taxes. It charges buyers a $20 commission -- not much for a $10,000 trip, but a lot if you're trying to score a $79 hotel room.

Named to multiple ''best of the Web'' lists, Luxury Link has a satisfactory record with the Better Business Bureau.

• eBay (www.ebay.com/travel), based in San Jose, Calif., fights fraud by limiting who can sell travel on its site, said spokeswoman Kim Rubey. Vacation packages, cruises, airline tickets and trips must be sold by licensed travel agents or businesses that own travel property (an airline or hotel, for example).

Individuals are limited to selling travel vouchers or travel gift certificates and even then, they can sell only one per month. Also, the voucher must be transferable and cannot be travel club memberships or ''travel choice'' certificates. Under certain circumstances individuals may list a timeshare they own for rent.

EBay has a satisfactory record with the Better Business Bureau.

• SkyAuction (www.skyauction.com) is a New York-based travel site that auctions hotel rooms, trips, airline tickets and more.

In business since 1999, it charges a $20 commission to buyers. It started off concentrating on airfare auctions but now offers a wide assortment of travel. It is popular with travel auction fans.

• Generous Adventures Travel Auctions (www.generousadventures.com) is a nonprofit based in Homer, Alaska. When you buy a trip, the company donates 100 percent of profits (about 45 percent of income) to charities.

Described by Frommer's travel guides as eco-friendly and ''one of the good guys,'' it is the only all-travel online benefit auction. It auctions everything from kayak trips to backpacking adventures to vacations abroad. The site is not rated by the Better Business Bureau.

• Bidding For Good (www.biddingforgood.com), based in Cambridge, Mass., is a site used by many nonprofit groups to auction off trips, airline vouchers and vacations (as well as other items) that have been donated to the groups to raise money. The site is owned by cMarket, which has a satisfactory record with the Better Business Bureau.