[angdis]

There are many things that influence how much it costs to transport people or anything else-- including weather, how much taxiing is involved and the style of the pilot.

I am sure the airlines have taken this variability into account. No need to make ticket pricing even more elaborate than it already is.

If they start discounting for thin folks, then they'll be criticized if they adjust the ticket for bad weather conditions and/or lead-foot pilots as well.