How much oil can cost?

[tama]

The energy contained in a gallon of oil, which costs about four dollars, is equivalent of the energy of, say, about one month's manual labour, wich costs, say, about 2000 dollars. These numbers are approximates of a generalization, others can provide more exact versions. What is also of crucial importance, that as EROI (energy returned on energy invested) of oil keeps weakening, a gallon of oil replaces smaller and smaller time of manual labor.

However, what should be clear is that the upper limit of price of oil or other technologically produced energy is the amount of manual labor it replaces - ie, in the example above, gallon of gazoline could go up to 2000 dollars before hiring manual labour to do the same job would become more competitive. Also, the upper limit keeps coming down as the EROI of oil keeps weakening.