Airline pricing in general is pretty opaque. Not hospital pricing opaque, but still pretty opaque. It's one of the few things we regularly purchase where the price changes almost daily (both up and down). For example, bus and train tickets are pretty much the same price each day for the same route. For airlines, I'll often check the price on some future night to see if it is cheaper or not.
Like medicine, the price is a negotiation point in a complex web of probabilities. Air travel can be more transparent because the probability network is simpler and the spread is narrower, but they’re both dealing with realities of providing predictable service under volatile demand and group payer conditions.
Distance train at least may (or may not depending on location/country) be quite a bit cheaper for advance purchase but maybe doesn't fluctuate as much day to day.
