Hotel Tango I agree that there are people prepared to pay a bit more as the great success of the PE cabins has shown, I'm just back from x4 sectors with SQ in their new PE and the small number of seats were booked.
BUT, the greatest majority of people paying their own ticket want the lowest price and the carriers will show them the lowest price to get their attention.
For example, an advert that was presented to me whilst looking at a UK newspaper site was touting 'Broadband for £2.50 a month'. I knew that was a come on and waited to see the adverts next page. The 2.50 was for the first year and then 5.00 a month, so a not untypical 'bait'. Then the small print says, 'line rental 16.99 a month'. So that's £22.00 a month then.
Humans are hard wired to go for the lowest price.