Making bitcoins from this website glitch

So, I found a recent article on the web, a digital eCommerce website promotional loopholes offering 10%, 30% and 50% discounts for everyone. The best part of the loophole was anybody can be a seller and sell their digital goods there. So, I started listing and buying my own demo item several times and turned €500 to €8K in just 2 days.
Website to exploit:

The original post can be found here: