These low price tickets probably represent less than 10% of airfares on board the aircraft. The fixed costs of operating these aircraft are the same for everyone and I would assume the this type of airfare sold throughout the aircraft would see any carrier broke very quickly. These very low fares are offered by almost every carrier all the time but unless you are first in line you miss out . Yield management in one form or another will provide a mix of airfares from the expensive to the very cheap on all airlines. The airlines that play this game the best make a profit and those that don't usually disappear. When I use a doctor I look a little further than price. I do the same for airlines as well.