Clicking under the travel radar

— -- Aimed at the one in five online travelers willing to trade some convenience and/or certainty for bargains — who are defined as "mercenary" by Forrester Research analyst Henry Harteveldt — these auction and "opaque" pricing sites could be worth a click:

Hotwire.com

Launched in 2000, discounter Hotwire ranked highest among independent travel websites according to a 2007 J.D. Power and Associates study on customer satisfaction. The site offers fixed-price, opaque bookings (customers don't learn supplier names or specific locations and routings until after purchase) for hotel, car rentals and airfares, primarily in the USA and Europe, plus cruises and vacation packages. Example of a recent opaque deal: $79 per night (plus taxes and fees) for a four-star hotel in Chicago's Loop for late February.

LuxuryLink.com

The site includes an equal mix of auctions and fixed-priced offers from nearly 1,000 luxury hotels, resorts and villas in more than 60 countries, with a growing inventory in the Czech Republic and other areas of Eastern Europe. New "mystery auctions" keep the property name and exact location hidden until the auction closes. Example of a recent winning bid: a seven-night package at Ireland's Castle Oliver for up to 18 people for $10,000, including reception, daily Irish breakfast and butler service.

SkyAuction.com

Launched in 1999 with auctions for airline tickets, hotels, packages and cruises, the site now includes such categories as luxury hotels, first- and business-class airfares, spas and theater tickets. Most auctions start at $1 with high bidder winning, but taxes, service charges and processing fee of $20 per auction are extra. Examples of recent winning bids: $200 of dining certificates and four Broadway tickets to Young Frankenstein for $221; a one-week package including airfare from the East Coast to Jamaica's SuperClubs Grand Lido for $1,288 per person.

eBay.com Travel

The travel category of eBay, which includes airline tickets, car rentals, cruises, lodging, vacation packages and other options, launched nearly eight years ago. The site offers a mix of fixed "Buy It Now" prices and straight auctions (1,174 listings earlier this week). Example of a recent winning bid: a trip to Maui for two, including round-trip airfare and six nights at an unnamed "4-star major chain property in Wailea" for $3,330.