I have a Windows 8.1 15" Lenovo laptop with AMD A6-6310 APU that I paid 360€ a few year ago.
It was the cheapest with best performance I found at this time.
I can enjoy playing games like Oblivion, HL2, Left4dead2 and Portal2 with it.
I use it to dev my main 3d game project on it and i get good performances even when I toggle the eco mode (which lower the max CPU frequency from 1.8GHz to 800Mhz).
Some laptops based on this APU are still available at price around 400€ here.
I've also seen some recent laptops with an Intel Core-i3 CPU and a Radeon R5 GPU at around 450€.