I've used SkyAuction before successfully, and will agree heartily with the above: Check ALL the addons! I had successfully bid and purchased two roundtrip, nonstop Virgin Atlantic tickets from Miami to London in August for $250 each. Plus $50 each for being out of Miami, Plus $100 each for taxes. However, $400 each is still a stellar deal for peak time on VA on that route! As an aside, these ARE prepaid and nonrefundable, just like Priceline! I was actually able (due to a doctor's note forbidding me to fly overseas due to a tough pregnancy) to get a refund (minus $50 per ticket) for these through very helpful people at both SkyAuction and Virgin -- but it was definitely an exception, and took lots of work.