You can probably save some money on the motherboard by getting one with an 880 or even the 970 chipset where the latter would give you CPU upgrade options and built in USB 3.0 on the chipset. This might shave the cost down to -- $100 for the motherboard. Crossfire is not an option though. My suggestion: http://www.newegg.com/Product/Product.aspx?Item=N82E16813128519
This may or may not be too much of a help, but if you are looking for an ATI graphics card I would say to buy a $140 Radeon HD 6850 as this will play near high if not ultra settings on standard resolution, then once you have the money for another you can crossfire it and have a system set for a surprisingly low price.
I believe there will be a bottleneck at about the range of 6850 or 460 between the CPU and the GFX card. Going higher will net you so limited benefits. It is the same with the i3. If you wish to go higher in terms of graphics you will need an i5 2400
I was wrong, i just checked it out. There is no bottleneck untill 6950. (Though there still is for i3 should you consider. I'd go for i5 2400 in prospects of 6950 or with i3 2100 and 6850 knowing that i would never upgrade this build)
There is no reason to go with that gtx 430 that was listed, when you can get a 6870 for cheaper. Battlefield 3 doesn't require a very strong cpu it is a very graphically intensive game. If this is the main game you wish to play you could probably drop the cpu down to a athlon x3 and put as much muscle into the gpu as possible. You may be able to squeeze a 6950 1gb in that range.