I can confirm that Gamestop does not sell booster boxes. The best they sell is Elite Trainer Boxes. I can not however speak for Target or Walmart, but I don't think they do either. I usually buy my booster boxes directly from Pokemon via the Pokemon Center website. Source: I work at Gamestop.
I apologize as I know I just messaged you, but then I stumbled upon this. I desperately need a Diancie! I saw that you have some, would you be willing to trade me one?
So here is the thing, many of us have played a gen 1 games. Either the original release, FR/LG, or Virtual Console. But for some this will be their first step into Kanto. Which makes sense for a new system when you think about it. Yes, I would have liked Gen 8 myself, but I'm not gonna hate on...