--How are you planning on purchasing everything? All together, same day, in a few weeks, or could it be over a couple weeks?
--Given the time of year, black friday and all, you can save money by watching for deals. Make sure you sign up for newegg and ncix mailing lists.
--watch slickdeals.com
--Cases and power supplies are easy to get cheap if you watch for them. Especially if mail-in-rebates are okay. Last week I got a rather cheap, but perfectly fine, case for $50 dollars with 2 rebates equaling $50, essentially making it free. That's pretty rare, of course, and a bit of a risk, but I see at least 1 or 2 descent mid tower cases for $20 every month on newegg. Power supplies work the same way to a slightly lesser degree.
--Whenever you buy anything go to fatwallet first and find their link to newegg. They offer cash back by using their hotlinks. It's reliable and you get about 3% back. It takes about a month after each purchase before you are eligible to transfer the funds to a paypal account.
http://www.fatwallet.com/?referral=varriform
That is a referral link from me, but it is not necessary to be referred by anyone. If you find this information useful than by all means use it, we both benefit from it. Completely up to you
--Don't rule out the Intel i3-3220 or i3-3225
http://www.tomshardware.com/reviews/fx-4170-core-i3-3220-benchmarks,3314-8.html
http://www.tomshardware.com/reviews/gaming-cpu-review-overclock,3106-3.html
It's only 55 watts, meaning you could save money on a power supply. And it's better in many respects compared to similarly priced AMD offerings.
--I'll do a very quick build just to give an idea parts at current prices. Keep in mind that today (Monday) is probably the worst day for deals at newegg. Least amount of overlap since weekend deals and previous week deals have ended.
Corsair CX500 - $30 after code and $20 MIR
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139027
Intel i3-3225 cpu and Asrock Z77M motherboard combo - $206.98
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.1098640
Rosewill Redbone Case - $32 after code
http://www.newegg.com/Product/Product.aspx?Item=N82E16811147159
Optical drive, well there's almost always one for $16.99
Ram, honestly a bad day for it. Later in the week should see an 8gb (2x4) 1600 1.5v kit for $30ish
Video card (prices change rapidly)
Sapphire 7770 (or any 7770) - $112 after rebate
or
XFX 7850 (or any 7850) - $170 after rebate
http://www.newegg.com/Product/Product.aspx?Item=N82E16814150619
OS - watch deals closely because prices are expected to hit at least $50 for Windows 7 during black friday deals. With windows 8 out Microsoft is trying to push 8 like crazy and clean out 7
--Note: the reason I suggested a Radeon 7770 is that video cards are easier to upgrade than processors and motherboards, in my opinion. The resale value is descent and it's only a matter or switching the card out. Plus, the 7770 is not a bad card and can play any modern intensive game at high settings (could be a couple exceptions). Just something to consider. I would choose the 7770 and spend the saved money on a cpu if it was my only computer. As a gaming machine you would definitely be better with a 7850 though
New AMD benchmarks since October performance driver release:
http://images.anandtech.com/graphs/graph6393/51047.png
http://www.anandtech.com/show/6393/amds-holiday-plans-cat1211-new-bundle