I would go with i5-3570K, for processor. Better performance/features + better match with your mobo. Am in UK, so BioStar not commonly used, but seems OK, for the money, although crossfire support is limited by second lane only being x4. Can't comment on quality.
The 2GB version of GPU is generally regarded, as much better than its 1GB counterpart.
nice! your build is really similar to my $800 one. The i5 2500k you have chosen is good enough for a gaming rig. The major improvement on the 3570K is about integrated graphics chipset and the smaller die architecture but those do not justify the cost over the last gen. Moreover, you actually only get a minor increase in performance to actually notice any difference. Also due to the cheaper internal thermal layer, the 3570k is a bad overclocker.
Now on the changes, you could go with an Asrock z77 Pro3 for a similar price if Biostar is not your committed choice. I do have an office who build 30 systems using Biostar motherboards and I asked them why. They said none of those boards have failed them for the last 3 years in another office not sure if I'd take their words for it because there aren't many of us use Biostar to give a solid feedback.
Lastly, why don't you consider a SSD as the main drive for now to get the best performance from the system since all other components are pretty promising? You can always add a secondary storage in the future when mechanical drive price drop a bit more. Cheer !
p.s : food for thought :
It is often to get confused that the higher count of memory can justify the real speed and power. But that is not the only one cause. The amount of memory on mainstream gaming video cards plays a relatively small role and does not make a great impact on the performance, in most environment settings.
On the flip side the type of memory does matter. On-board GDDR5 is a lot faster and more responsive than older DDR3.
You must also look in to the number of CUDA Processors (NVIDIA) or Stream Processors (Radeon) and know how fast the core clock speed is. These are the two significant elements that essentially determines the real-life performance of the video card.
To be honest, I would put the arguement the opposite way round. With only a $5 difference between i5-2500K and i5-3570K, it would be madness NOT to use i5-3570K, with that mobo. I would make the following points.
1) That board is designed for Ivybridge. Whilst it will work with SandyBridge, if you are using SandyBridge, you might as well use a 6 series board.
2) The i5-3570K has about 8% performance benefit, over 2500K, at stock, and like for like overclock. True, it is possible to overclock SandyBridge more, but you need to overclock, to at least 4.8GHz, to see any real benefit. I don't know what that particular board is like, for overclocking, but some cheaper Z77 mobos do not overclock SandyBridge well.
3) Ivybridge provides native support for 1600MHz RAM, which SandyBridge does not.
4) Ivybridge has lower power consumption, and produces less heat, with modest overclocks. Not that it's a huge gain, electric costs are slightly lower. Not a lot, but it doesn't take forever to get your extra $5 back.
5) Whilst many of the Ivybridge benefits are "fringe", for out and out gaming, they are there, and, all other things being equal, prefer newer tech.
Ivybridge doesn't make sense, as an "upgrade" FROM SandyBridge, but for a new build, definitely worth it.
Oh no, I actually agree with you if the price difference between 3570k and 2500k is only $5. By all means, go for it. I had a chance to delid the 3570k and applied the MX-4 paste for better temperature when overclocked, it ran a lot cooler in that case. I still have an impression that the price difference is over $50
Now about Microcenter deal, my bf works there and I know a bit about the current 3570k + $50 Off motherboard. So instead of i5 3450 for $150 and a full price motherboard, why not the i5 3570k ($190) and -$50 from motherboard? It is the same cost
Apart from needing an aftermarket cooler, the cost, at Microcentre for say i5-3570K + ASRock Z77 Extreme 4 is no more than i5-3450 and H77.