An approximation or estimation of a unit to the closest 100 denomination. "abou" is a reference to this approximation and is an abbreviation of 'about'. Standard rounding comes into play which becomes more clear in the example given.
If you were asked how much money you spent on your new hi-fi unit and could not recall exactly but were sure it was between $120 and $130, then you would remark that "it cost me one hungeabou".
However if you estimated or recalled that it was between $160 and $180 then it would be considered "...two hungeabou".
In a game of poker :
"how much are you in for?"
-"awwww.... three hungeabou?" whilst counting your chips.-