I have a couple of questions about the Pokemon card machines and how they work?

I'm not trying to buy/sell/trade or determine the value of a card/box, I just had questions pop up in my head after using one.

Well first of all it seems like the prices are extremely reduced on them because there isn't another store buying and selling tnem at a higher price. But i didn't realize the price difference could be as huge as the one I got today. This box was $173 from the machine and it goes for $250 on average. Is this why the scalpers target these machines so much? It was my first time buying from one, but if this is what the scalpers fight each to death over it's pretty funny. So much effort for like a $70 flip.

Two, is it real that the machines reset every couple of hours?? Because I've seen some weird things happen. When I bought this box today it had originally said it was sold out so I bought a different box. Then, magically after that, the box that was sold out just happened to be available now. They are very confusing. I'm happy I got my box it's just weird how the box changes its mind if it's sold out or not.