real.geizterfahr: Nope, they won't cost you. A FX 6350 won't be able to run any strategy, open world or AI heavy game in two years anymore, no matter what GPU you put in your case. And your GPU will scream for an upgrade that your CPU can't keep up with.
ET3D: What do you base this assumption on?
The fact that it already is limiting heavily in CPU intensive games!? Just have a look at some of them (average fps)...
Total War Rome II (37 fps with GTX Titan)
Skyrim (~30 fps with GTX 580)
StarCraft 2 (45 fps - 1024 x 768 - Medium Graphics, Ultra CPU Settings)
Project Cars (46 fps with GTX Titan X)
Strategy games, open world games and other games with lots of AI activity, don't like the FX 6350. Skyrim and StarCraft 2 are almost antique by now and they were already dangerously close to the 30 fps mark back then. And Total War Rome 2 isn't that new either. It doesn't take a lot to see that a FX 6350 won't handle new CPU heavy games in two years anymore. It alwayys was a slow CPU. It won't get faster in the future.
ET3D: And even so, what you say implies that for a player who sticks to AAA action titles the FX-6350 will not be a serious limitation.
Uhm... Of course it won't limit a game that doesn't ask a lot from the CPU until it's
unplayable (<- that's what "won't be able to run" means). The new Doom gets 98 fps out of a FX 6350 when paired with a 980 Ti. That's a huge bottleneck for the 980 Ti (142 fps with i7 6700), but still comfortably playable. Compare this to the 46 FPS in Project Cars (a four years old i7 CPU doesn't limit this game at all).
ET3D: Based on the past, the FX-6300 was a bottleneck in some games even at release. At that time the high end GeForce was the 680. Later it was still a bottleneck and the high end GeForce was the 780 Ti. Now it's still a bottleneck, and the 680 is about as powerful as the 960 and the 780 Ti is about as powerful as the 970, which you said is a good match for the CPU.
A GeForce 980 will likely be a bottleneck for the FX-6350 in two years time. We have an entirely different understanding of the word "bottleneck". The 980 will NEVER be a bottlneck for a FX 6350. It'll become a bottleneck in certain games, yes, of course. But it'll always be the FX 6350 that bottlenecks the 980. The 970 is a good match if you take the average of many games. It'll become bottlenecked by the CPU in strategy games and it'll run at 100% load in Doom or Call of Duty. But on average, it's a good match.
ET3D: Sure, I agree, at some point buying a new CPU will be worth it, because it will be too slow. Until then not being cheap on GPU's is the way to go, because they will always grow to be a bottleneck.
I still heavily disagree with that. It's stupid to get a new GTX 1080 to reach 60 fps with a weak CPU in a game, when you could take these $700 (or whatever it is) to get an i7 (doesn't matter which one) and a RX 480
for less money and still get the same 60 fps - in basically every current game! Sure, you can beat your CPU to death with a huge sack of money. But this'll only work in games that don't ask a lot from the CPU (no six years old Starcraft 2 for you :P) and make your new GPU die of boredom (25-30% GPU workload).
Seriously, kids... Don't spent hundreds of Dollar on a GPU if you have an old, slow AMD CPU.
ET3D: Sure, but this has nothing to do with whether you buy a GPU at $150 or $200. Unless you're trying to claim that one additional month in 2 years is really significant.
If you want to spend an additional $50 on a theoretically (fictional numbers) 15% faster card that in reality will only be 8% faster because of your limiting CPU -> Go for it and be happy. All I say is that I wouldn't do it and that I'd put the $50 aside for a new PC. Do $50 make a difference over 24 months? Maybe, for some. If they don't: Take these $50 to get your new PC one month earlier ;P The FX 63xx CPUs weren't that great when they were released. They didn't become better over the years. They're limiting heavily in some games already, so burying your CPU problem under a pile of GPU money will only help you with games that are easy on the CPU. But as soon as you play a CPU heavy game, you'll regret it.
We do agree that a GPU is more important for gaming than a CPU. And everyone who has at least a 3rd generation i7 CPU (i7 3xxx) won't have to think about CPU bottlenecks (i5 users start to note the missing hyperthreading). But the AMD CPUs we're talking about here, are crap. They were never good and they didn't age very well. You can't overcome their flaws with more powerful GPUs, except you want to spent $700+ (Titan X, GTX 1080) and never play anything else than Doom or Call of Duty.