Okay, now I am getting suspicious. I've discovered yet another game in my collection that I've re-bought. RoboWarrior for the NES was a game that my VG collect said that I had, and I thought I had, last year when I bought it. Turns out, I have photographic evidence that I did in fact buy it once before, for $3 in 2012. Yet I can only account for my more recent copy.
I think someone might have stolen a few of my games, probably several years back. I was in a jam band of sorts, and I hosted practice at my place. But I always felt like everyone who came over was trust worthy, maybe not? This is the second game, and I bet I'll find a few more. Odd choices, because so far, none of them were, or are valuable games.