Sorry, I wasn't clear. They weren't talking about full fare.

Example quoted below:

"A few weeks ago, I was checking New York-London on American for the Fourth of July weekend and was offered a lowest price of $1,450, not including taxes and fees. Without restrictions, the lowest coach price was $2,910 -- full-fare in coach. But ExpertFlyer found a B-class round-trip of $1,644 without taxes, which was only $194 more that the cheapest coach ticket. If you upgrade, you'd save more than $300 and 30,000 miles over buying the cheapest fare. And if you simply wanted the flexibility of a fully refundable ticket, you saved more than $1,200 by buying B-class instead of a full Y-class fare."