With a budget like that, you'll be hard pressed to get a real mind-blowing upgrade. If you're satisfied currently with your gaming/rendering performance graphics wise then going with a 128/256 GB SSD is the way to go. The Samsung 840 Pro, Kingston Hyper-X, among others are great SSDs. This way you could copy over your OS to the SSD, thus boosting your boot time ten fold. If you move your apps you use the most to it as well you'll notice worlds of difference in loading times.
If you are wanting to go with more of a Dedicated graphic card approach (since you are just running the integrated chip on the A10 CPU), on that budget I would strongly recommend an AMD7850/7870 (AMD beaats Nvidia hands down for Rendering purposes, but at that price range Nvidia has the advantage in gaming).
If you would like I could post some links to the items I am talking about or feel free to message me on here or Skype (on my profile).