The Obione configuration seems generally quite correct to me. You could scratch a little by putting in a slightly cheaper motherboard, a cheaper cooler as well, but in general you would lower between 40-50€ from one side to the other
Then if that budget is high, don't buy the SSD, and you can mount a cheaper graphics card, but from about 700-800€ you can mount a pretty good gaming PC.
If you don't want to upgrade in a good time an AMD FX is a good solution without going out of price. Otherwise, to notice a change you have to go for an I7 and already between micro and motherboard the budget would go up by about 150€ or more.
To play today in general an Intel I5 is better but, some games like BF4 use AMD micros like FX very well and perform very well.
The FX-8320 goes to 3500 but they all easily go up to 4000-4200 with good ventilation. I have an FX-8350 because my previous FX-8320 blew up and they changed it for this one, otherwise the FX-8320 is more than enough, don't buy the FX-8350.
Next year there will be new micros, DDR4 memories... but if you wait until the end you won't enjoy the computer and there won't be a very big change in power in principle so that PC should last you a few years. If in the future it falls short, you put 8 more Gigas of Ram.