It was a cluster f*ck.
I was at the webpage the moment Soldner was available online. The product description listed it at 75%-100% stock left when I added a copy to my cart. I clicked on Paypal checkout and the next page said the game was out of stock. I returned back to the product page where it said the stock was now less than 50% left. Added the game to my cart again and the same thing happened with Paypal checkout. I tried over and over to get a single copy of the game and couldn't get one, despite the product page saying there was still 25% left. I kept getting the out of stock screen despite clicking on the normal checkout button or the Paypal checkout. I tried about 15 times before the game was listed out of stock and you couldn't add it to the cart anymore.

Fast forward to later in the day when the second batch came available. Same EXACT thing happened. I could add it to the cart just fine, but clicking checkout said they were out of stock. I tried this probably about 40-50 times before the game was sold out. It even gave me the sold out screen when the product description page said there was still 10 copies left.
Really disappointing as I wanted a physical copy of the game. I did everything right on my end.....was at the product page minutes before it was available both times, was able to add it to the cart, but still got told it was out of stock.
Really bugs me that those who were able to actually purchase a copy were able to buy two of them.
They posted on their forums that they are looking into it as what happened to me seemed to happen to a lot of other people. Really disappointed.