For gaming a $60 G4560 would easily outperform that 6300, the FX CPU's are really outdated and even at release they weren't very good. As for getting the OS Key from Kinguin, good luck, we see quite a few threads about people who buy "cheap" keys that seem legit and eventually MS finds out its a fake or duplicate and invalidates the OS so your out whatever that key costs you. MS allows you to use Windows 10 for free, that's your best option until you can buy a legit key from MS or a authorized retailer.