2. I assume you're aware that the latest Intel CPU's are 22nm and generate far less heat (thus your system will be MUCH quieter under load). When overclocked the AMD CPU's can generate up to 100 Watts more and cause the CPU fan to be far, far noisier.
3. Don't forget when you change the MOTHERBOARD that you also need a new copy of Windows unless you bought a FULL copy that can be transferred to a new PC.
4. If you ALSO GAME that may change your decision as well since the Intel series would be better.
My advice would be the i5-3570K for the following reasons:
1) It's slightly faster than the FX-8320.
(The i5-3570K could be overclocked to 4.5GHz max with that CPU HSF. While the FX-8320 could theoretically clock to higher than this, you would need a good motherboard and BETTER cooling solution which adds to the cost.)
2) It uses less power (will actually make up for the increased cost over time).
3) The PC will run quieter.
4) Better CPU for gaming as well if that's an issue.
My advice is:
- inexpensive, but quality 1155 motherboard
- Intel i5-3570K
- obviously shop around for deals/bundles (you mention Microcenter but there's NCIX, Newegg, Shopbot etc.)