An FX-4100 has a TDP of 95W, a 560TI 170W, which means you'll draw maybe 300W in an artificial stress test. If you doubled the TDP of the FX4100, which would be a huge OC, you'd draw maybe 400W in an artificial stress test. Gaming would be more like 250/350. So even as the PSU aged, you'd be okay on a CX430 with a modest OC , which is all you'd be looking at without some expensive beefy mcbeefy cooler anyways. In short, I'd be surprised if your system, when all is said and done, is drawing more than 300W in gaming, and a little over in a prime95/Furmark test.
Is it a good system? Clearly there are differing opinions there on what qualifies as a "good" gaming system, but if you can land an FX-4100 even without OCing, a 560ti, and 4GB of any DDR3 under the sun, you'll have a *capable* gaming system for two or three years (my best guess). You'll have to play some games with reduced settings, but you'll be able to play, and smoothly. MWO is a worst case scenario, and it might drop into the high 20s or low 30s (probably on a med/high mix for settings) in the worst situations because of the CPU, higher if you OC. If that's really as good as it's going to get with your budget, and believe me, I understand budgets, then by all means, go for it. It's better than what a lot of people have to game on, and that's very, very playable.
Edited by Catamount, 29 May 2013 - 09:23 AM.