If none have been sold before, aside from the copy on emp, for $71.00 USD, then that value is a good starting point, as the collectors themselves kind of set that value. And since it's also described as an export poster, that might also have some affect on the final bid price (similar to those that were printed in the US but meant for the Spanish speaking markets).
Remember, too, that rare doesnt always translate into expensive.
This poster needs a little TLC but Id be tempted to keep it as is, tho, in there was a way to repair the couple larger holes that are in the title, I'd look into that (if there was a way to "spot repair", that is).
Were you the winner of this poster? If so, congrats.
It's rather cool looking, I gotta say. Since this is called an export poster, I wonder if there was another style that was designed & used specifically for Mexico? It would be cool to locate an image for that, too.