Built a PC at the Beginning of Jan:
Spec:
CPU: Intel i5 3570K @ 4.5Ghz
CPU Cooler: CoolerMaster Hyper 212 EVO
Motherboard: Gigabyte GA - Z77 - D3H
Memory: Corsair Vengeance 8GB
Video Card: MSI Twin Frozr III HD 7950 OC @ 1000/1575
Sound Card: Asus Xonar DGX
Power Supply: Antec True Power 750W Hybrid
Case: NZXT Phantom Full Tower
Monitor: BenQ XL2411T 144Hz
Now all this cost me over £1000, but this is all overclocked and can run Crysis 3 Ultra at around 30-60FPS.
Battlefield will run High to Maxed settings with an i5 and a HD 7850, in my opinion you are better off saving and spending a decent amount on a PC so it is future-proofed as games will come out in the future that you will wish to play considering that developers now are stepping up the game with new engines, i.e Unreal Engine 4 that will require some next gen hardware.
Best place to look around, ask and get some good info would be Overclockers.co.uk and reddit.com.
Also I found PCPartPicker.com helpful for selecting parts and getting a rough estimate on hardware prices.
Sign up and post a thread on Overclockers.co.uk titled 'Help with new build', everyone will help and give you some complete setups!
Tom After all that I read the title, 'Updated Bought a Laptop'!