I concur in that the fault does not detract from the stamp's presentation in an album. The irregular margins are an aesthetic judgment.
It comes down to whether you think you'll be satisfied with it long term, or will you be wanting a sound or more appealing example at some point? I don't know what the rest of your collection looks like from a quality perspective.
The R33a is actually not that difficult to find in nice condition, although you'll pay more. Even so, I might hold out for one with a bit better presentation.
For the sake of comparison, here is one I purchased in March of 2013 from Kelleher auctions. It too has a hole, but in my opinion, the margins and centering make it a great visual example. Including buyer's premium and shipping, I paid $102... not that much more than the stamp in question being offered to you.
Any time I am offered a stamp, I check to see what comparables are currently available on eBay