Terrible CPU ... Insanely expensive RAM ... Too costly video card ...
Are you sure about this system mate? Other's systems are much better than this one and cost nearly the same.
You can go for envy's system if you are not into overclocking and it would perform far better than any of the Richland CPUs out there.
If you want to overclock, reduce RAM to 8 GB and add i5 3570K along with Z77 motherboard. Price would be same.
Don't go for AMD CPUs mate, they are terrible.
When it comes to CPUs, go for Intel for performance. When it comes to GPUs, go for ATI for money.
In your build, change CPU to one of the good Intels, go for 8 GB RAM (2 x 4 GB) that is more than enough and if needed you can add more later, and GTX 770 or Radeon HD 7970 instead of 670. If you want more value for money, go for Powercolor Radeon HD 7950. That GPU is a beast too and can max out most of the games out there. Retails for around $300.