So is an fx 8320 just an 8350 with just some messed up transistors?
The 8320 is a lower binned, arguably lower quality chip. Basically, AMD made lots of these chips that will become either 8350s or 8320s; the ones that naturally have a higher curve frequency-wise, those become 8350s. The ones that are a little worse, those become 8320s. They are literally the exact same CPU, just different clocks.
I'd grab the 8350. Not sure about the costs , but from looking at the model numbers , the higher will be better . By buying the 8350 , you'll get performance which matches and beats the i5 3570k and probably save a bit of wonga.
What is this "wonga" you speak of?
Money ;)