I remember paying, circa 1980, as low as $99 to fly San Fran to New York, and $199 to fly San Fran to Hongkong. Service was still OK; the cheap fares were possible in part due to a two-tier pricing model…
But anyway, I stand by my basic point even if the specific example is subject to debate. 
Well, the CAB started phasing out route regulation in 1978, so I’m sure there were deals to be had amidst the chaos. 
Plus $99 in 1980 are worth more than $99 in 2012. But yes, already by the late 70s-early 80s the low-fare carriers (see: Freddy Laker) began moving quickly to be early adopters of the new scheme and many of the legacy carriers responded by loss-leading on the popular routes. In the end the argument stands: the mass-market customers proved that what they wanted was low fares and a reasonable performance and that they were quite happy to go “no frills” if it meant the $89 ticket was a consistent thing and not just a once in a while bargain.
The vast majority of customers are honest, fair and understanding. They pay the price for what they want. I work as an associate (read clerk) for a small local home improvement chain. We have a niche clientele. We compete against the Home Depots and Lowes. Our clients shop our store because we provide extreme customer service. That means we answer technical questions, walk all customers to the item (not point them to the isle), and carry out an item that is large or bulky. We are also extremely friendly, willing to talk to the customer and yes we greet all incoming customers. The big boys try and copy us but by the shear size of their operation they can’t quite pull it off. Not a day goes by that several customers will comment why they prefer to shop with us and try not to go the Walmarts, Home Depots or Lowes. In most cases our customers are always right because we convince them they are right.