Actually, there's no match of i7 3770. No AMD CPU is even close to its performance. And, this situation will persist until, the applications will actually support multi-threading upto the extend to use all the 8 physical cores.
Hmm I would go for an i3, though the FX 6300 isn't bad considering it is a triple core for only $10 more than the i3 3220. Even a Pentium G2120 or A8-5600k wouldn't be bad. I would go for an SSD though, as that is what would improve your computing experience the most.