This is a pre-built pc that I want to upgrade to handle next gen gaming. My budget is around $250 to $300 but if you want to increase that a bit then go ahead. APU: AMD A6-6400K APU with AMD Radeon HD 8470D
If you can wait a bit longer with an upgrade, then i would recommend to save some more money. And do a complete mobo + cpu + GPU upgrade. Saving a bit more money, and do a bigger upgrade would be better in my opinnion.
Sell that prebuilt for whatever you can and be rid of it. That APU was not great when it was first released, and it's definitely gotten worse now. And your PSU in that pre-built probably has no headroom left over for upgrades.
When you do decide to sell that thing, save that and some more money for an actual PC build.
Do like MisteryAngel said and get a 860k. I would also get a 270x. Main thing here is you need a quad core. You could eveven do a 5350 build with a 270x.
In all honesty if you're trying to 1080p save up some money and do it right. 600 dollars should last you 5 years. I'm sure you can budget your money by not eating out or going to the movies.
That is unlikely unless you have a tiny brick sized PC, If you don't know, assume 200w - 350w. Also if you don't know, assume the PSU that came with your PC will not be enough unless you can get confirmation of wattage. The easiest method is to open your PC, take a picture of it, take a picture of it from below/above, and take a picture of it from behind and post them on here for us to find out.
There is only so much you can do with your machine and throwing $300 or so at it will be a waste. If you wanted moderate gaming in the meantime on the cheap, get something like a 750ti or a HD6450 for xfire with your APU.
I like the size of the case so I guess that's the only thing I'm keeping. I was hoping at least one of the parts was good enough to be kept but from your replies, I think just discarding it all would be the best choice. The rest of the parts will be sold and I'll look up your suggestions. Thanks.