I collect Worldwide bisect covers and have a small collection.
btw - the 2015 Unitrade catalogs your cover at $500 so it has gone up in price. It is nice and has what bisect collectors want. The stamp is tied to the cover on the bisected side with dated postmark. Nice half of the stamp, too. I believe that many bisects come from a "need to use" situation. Someone has a letter and a 2c stamp, so to save money, they use it for two letters instead of one. Not many people wasted money in those days and a penny was likely alot.
Your cover was in the same time period as the Port Hood Provisional covers where the 3c Numeral was cut into 1/3 of a stamp representing 1c and 2/3 of a stamp representing 2c for use on cover so it wasn't unknown at the time, especially in the Provinces.
I just posted two of my Nova Scotia bisects on another site. Here is my fav of the two. I also have a bisected Canada 2c Numeral cover from the same time period as your cover and a few other Canada.

