I've used this service more than once and gotten precisely what I expected to get -- a reasonably priced roundtrip ticket that eventually got me to where I intended to go. The Fool's writer apparently believed she could pull a fast one on priceline by agreeing to a single stop -- after all, where could a plane possibly land on its way from New York to London? Well, Amsterdam, Frankfurt, and Dusseldorf all come to mind. Apparently, they knew more about the travel business than she imagined. She shouldn't be angry with priceline for simply adhering to the terms of its contract.
Fees a little high? Taxes more than she bargained for? Maybe. But it's all there on the Web page. $270 per person to London just isn't that bad a deal.
Moreover, after she related her sad story to various customer representatives, priceline agreed to a complete refund! That doesn't seem like crummy service to me. After she declined this gracious offer, took a few days off, then changed her mind, Priceline became a little less forgiving. But your average airline would have done exactly the same thing! "Non-refundable" means precisely what it says.
The key to using priceline is to remember just what it is that they are offering: cheap, discounted fares; no frills; seats near the back; and the possibility of driving several hours to reach your final destination. If negotiating a few extra hurdles is worth the savings, then priceline is a good bet.
If not, well, there's always British Airways.