Hmm....... I'd like to think that in using the words "ridiculously cheap", you do mean in comparative terms.

Fair to say that a majority of people would still consider the figure of $4000 as a significant sum to get through (especially if from personal funds) for one day of air travel. But your basic point is certainly well made by highlighting the huge variation in fare levels in relation to point of origin. Market forces .....supply & demand ...... sometimes they all work in your favour, but often not.