I believe that you are making the wrong comparison. First and foremost, the 4770k is (for the most part) replaced with the 4790k, and the two processors are leagues apart. In every way, the 4770k (and the 4790k) will outperform the FX-8320. Other added bonuses are the future-proof Z97 chipset (assuming that you're going with the 4790k) and the lower tdp. The 4790k does carry a hefty premium, though, at $339 compared to $159 for the 8320.
A fairer comparison would be towards the i5-4690k or the 4590. The 4690k, though a fair bit more expensive at $239, comes with all the benefits of the 4790k, albeit forgoing the nice 4 GHz default clock, hyperthreading, and 2MB of L3. For the large part, the performance difference between the 4690k and the 4790k is minimal. It is, however, unlocked (hence the k suffix) and can be overclocked to your heart's content. The 4590, on the other hand, is a locked processor at $200 with a slightly lower clock than the 4690k. Still, it boasts significantly better performance than the FX-8320.
If you are doing video editing or other heavily threaded tasks, it's a different story. Due to the lack of hyperthreading on the i5's, the 8320 holds its own or even surpasses the more expensive i5 chips. However, with gaming (which I am assuming your target is), Intel's single-core performance reigns supreme.
On the whole, I would go for Intel, either the 4590, 4690k, or the more expensive 4790k if you can shell out enough cash. AMD simply can't compete at the high end.
Note: I would recommend investing in a better graphics card instead of a processor for gaming or an ssd for general use.