Even gold Mario is common. I been seeing a guy trying to sell one on craigslist for over a month now for $40. Just sits there till he relists it, endless cycle. He'd probably take $20-25.
You and I have very different definitions of common. I will agree he wasn't super hard to get, but I wouldn't say he is common by a long shot.
I was about to say common means you can stroll into the store and pick it up for msrp. Gold Mario sells on ebay for the same price as Ike.