Earning Money from Proficiency Professions

A number of the proficiencies characters have access to say that they allow the character to work in an associated profession at a given wage.

Is the intent with this that, given a month of downtime, a character can just say "Okay, I am going to spend my month working as a [profession]", at the end of which time they gain the money? Or are the listed wages meant to represent someone in that profession who already has an established business and has been working for a bit?

I found a similar discussion: http://autarch.co/forums/general-forums/general-discussion/players-working-specialists