Well, for $300, a dual core CPU and a low end GPU would fit the budget perfectly.
I'm starting to get a de ja vu feeling about this $300 build...
For price, the AMD platform is the better option. With 300 bucks, you can get a decently clocked dual core CPU and better performing IGP. But since you do graphic, an IGP just won't cut it.
So here's the big picture:
Motherboard: If you're not a power user, get a basic motherboard with just 2 slots of DDR3 RAM (max. 8GB), it's usually cheap, around $50. ASRock usually made fine yet cheap ones. I recommend the ASRock 770DE3L model.
GPU: A simple 512MB HD4650 should give you enough edge before you decided to upgrade. It should also be around $40.
Memory: A value 4GB of DDR3 RAM costs around $50. Don't mind using heat spreaders if you don't OC.
DVD RW: Any will do. It's cheap anyway. Costs around $15
HDD: A 500GB costs nearly as cheap as the 250-320GB, so you might want to get one. In this case, bigger is ALWAYS better. Should be around $40.
PSU: A standard 350-400W from reputable brand should power up the rig nicely. Get a cheap but trustworthy one from FSP, Enermax or Thermaltake. Seasonic would be better, but just get the cheapest from any reputable brand. It should cost no more than $40, make that $30 (AcBel's 350W CE2 series) if you're lucky.
Case: Any will do: A $40-50 standard case is more than enough for such basic rig. Even a $20 one if you're tight on budget (HINT: I build 4 Internet cafe PCs using $10 cases, but keep it a secret, okay?
![;) ;)]()
). But if you don't mind using old parts, just use your old case. Same goes for your HDD and ODD if you have any.
Finally, the CPU: Get at least a n Athlon 2.8GHz II X2 240, the higher model the better. Buy the fastest your budget permits you. It should be around $50. I heard they even sell them for $40 somewhere, but definitely not in my country.
There you have it. With a little bit of luck, you can even get those parts under $300. I heard US is famous for cheap computer parts, you can use that to your advantage.
You're probably wondering, why didn't I give you any links to Newegg? Simply because I don't buy from them. More like can't, since I'm not from US. So I guess you just gotta hunt those combo offers and discounts by yourself.
Good luck!