Yes, exactly; it's not a round one, it's not unique either, as there are more than 10 pcs with the same mark/perforation in the lot I recently bought.
As I have about 10 pcs with the same mark, I think it's not a damaged note. About it's value, in accordance with the G. Cuhaj world paper money specializes issues catalogue, it's cost estimate is $135 in XF, thus I wouldn't take it as an inexpensive note.
Just a side note here since the objects are commemorating the Mexican Revolution. Last year I found a bronze ring while metal detecting and an archeologist who specializes in Spanish relics has examined it and is in love with it. It has a “coin” mounted on it and on the outside is a replica of an Incan calendar. But on the inside there is a face belonging to Father Miguel Hidalgo who is called THE FATHER OF THE MEXICAN REVOLUTION. He led the revolution until his capture, torture and execution by firing squad in 1811. The archeologist believes it was likely made in Vera Cruz and probably belonged to a Spanish priest. He thinks the face was hidden for political reasons. Note how heavily made it was. When do you ever see a ring with 8 prongs?
If you were to stack the 10 notes together, one atop another, would the perforations all line up, as if they were all made at the same time? or Are the perforations independently different from each other? Either way, the perforation(s) could be a form of cancellation mark, denoting that the bill is no longer in circulation, or is no longer recognized by the Central Bank. Never having seen those particular perforations before, I'm only guessing, although I have seen other perforations before, mostly round ones, that mean that same thing. If I'm not mistaken, over time, Mexico has demonetized many series of notes.
Yes, sure; I did understand your intention, there's no problem. In general the prices that similar notes were sold at HA are those in the market. However, some particular series are more expensive, as shown in the attached file.
As it seems on the image the perforations are equal in size & angle. I suppose it's a kind of cancellation mark, made for some reason we ignore...