[crc32]

I don't think this is an axiom of capitalism.

It might be an axiom of some models of capitalism. It would be very hard for an analyst to reason about a transaction if you were required to take imperfect information into account.

Interestingly, in a different model you might factor in the cost of obtaining information about the transaction; and still determine that it was more efficient for you to pay £75 than find the free Firefox.

You would still be rational. Just very rich, or perhaps extremely lazy. But you are not required to be omniscient in that model, only able to estimate the cost of obtaining the information.

http://en.wikipedia.org/wiki/Perfect_information