Yes these are all very good points. And in fact my oil analogy isn't so great because that is talking the about supply of a largely fungible commodity whereas

Yes these are all very good points. And in fact my oil analogy isn't so great because that is talking the about supply of a largely fungible commodity whereas with programmers the whole point is that different programmers have different skill sets. So it's lots of different markets that aren't really competing against each other (the market for quantitative programmers who know Haskell and financial mathematics vs the market for programmers who know lots about Java, Spring, Hibernate and SCRUM) rather than a single market. And that's a better explanation for why there are 10x differences in pay: the supply and demand in each "niche" is often very different (by an order of magnitude). If you're a programmer working in exactly the same niche as another programmer and you can prove that you're ten times as productive, then yes I suppose you could get 10x the pay... The trick is the first part though (proving that you're actually 10 times as productive).