Knufire found a deal at microcenter for 250 flat for an Asrock Pro 4 m + 2500k. That'd be an awesome start and great buy if it's still available. I believe that was the deal.. Just going off memory.
i thought it was a 3570k + pro4m for $300? or is the 2500k + pro4m a different deal. in which case i would save the $50 tbh and get the 2500k.
As i said before mate even buying off ebay your pretty safe getting a giga card tbh+ you have ebay buyer protection. Its a lot better nowadays!
if you are really working to a tight budget i would say going second hand might be the best way. idealy you rig would wanto to look like this
CPU: i5 2500k/i5 3570k
CPU cooler: again if you are on a budget either the cooler master hyper 212 evo or even cheaper the XIGMATEK HDT-S1283. Both cheap and will get you past the 4ghz mark on the 3570-k or 2500k ( probs even a bit higher on the 2500k)
Mobo: any z77 mobo (as long as you have all the right options in bios overclocking is all done via the multi now so expensive enthusiast mobos are being quickly redundant/ a waste of money)
GFX card: Try and pick up a 560ti that would be the lowest i would recommend to play bf3 @ 1080 with high settings.
RAM: 8gb ddr3 1600mhz ( im guessing this is the ram you have atm?)
Case: bah, wteva is cheap/ decent cable management
PSU: decent 500-600W ( corsair or OCZ are generally popular for lost cost reliable PSU's.)
HDD: 120gb SSD ( any will do, even the ocz vertex 3 as they have sorted the issues with stability etc in recent firmware upgrades, the corsair force series i also a good shout.D)
I know you a bit iffy about buying second hand but if you are pushing a pretty slim budget it might be the way to go. ( unless you have a microcentre nearby!) Both your gfx card and processor are things you can pick up dam cheap on ebay as long as you have a dig about. There are still plenty of deals about for 560ti's on ebay and if you get lucky you could pick up a 2500k for around $150.