Here's a build I put together earlier today. the 5870 is a great card, but I've never really liked it price/performance ratio. It's 33% more expensive than a 5850, but only offers a 10-15% performance advantage.
You're not gonna fit 2 5850's into your budget and definitely not a 5970. Still though, I've had no issues playing even Crysis at max settings 4xAA at 1920 x 1080 with a single 5850. I do have it OC'd to max Catalyst lets me, but 99% of 5850's can easily do that OC.
Also, you could wait a week or 2 to see if Fermi (coming out friday) causes ATI/resellers to drop prices.
OCZ Stealthxstream 700W and 7200.12 500 GB $114.98 http://www.newegg.com/Product/ComboDealDetails.aspx?Ite...
The OCZ PSU is a solid PSU for a low price. It'll handle xfire 5850's no prob. Spinpoint F3's are sold out ATM, but the 7200.12 comes comboed for a nice discount and has about the same performance for the same price.
The prices for the 5850 are already beginning to come down from some jacked up highs over the last month or so. I bought a 5850 in January for $299 (less $25 BCB), and shortly thereafter supplier jacked them up to $320-30+. With the release of Fermi coming in the next few days, the 5850 is back down to $299 with free shipping on mutliple models. I say wait and see if Fermi's actual release drops that down even further. It may as well since the card had an original MSRP of $259 back in October or so.
I agree with the builds above. Solid components, most of which I ended up using in my 1-2 month old build. These are parts I used, and recommend, that are all mentioned above:
ASUS P7P55d Evo
Ripjaws 4GB 1600
CM Hyper 212 hsf
Sapphire Radeon 5850 (you can use any 5850 basically)
Any optical drive
Don't buy a PSU cuz you don't need one. I have a Corsair 650, and its more than enough. I believe a single 5850 uses under 200 watts (something like 160 I think), and the ripjaws are low voltage. If you want to spend the $55 for a new drive, go for the one mentioned above, or a Samsung Spinpoint F3 500GB. They're the same price, and each are excellent drives. Personally, why spend money if you don't have to? I'd invest the savings in something more tangiable, like a new monitor (or two more for Eyefinity). The HAF 922 is a great case. I considered it, as well as a 900, but instead opted for the CM StormScout since I got it for $49 with free shipping at Newegg on Black Friday. It's a terrific case.
I agree with the poster above with respect to the 5870 vs 5850. The 5870 is $130 more. The price to performance ratio is really not worth it. The 5850 will run every thing on high settings as is. I'm currently running BF Bad Company 2 maxed out without issue. It's a kick ass card, and well worth the $299 price tag. In a couple of years when it's time to upgrade, put that $130 you saved toward a 2nd 5850. By then they'll probably be about $150-$200.
Yea, last few months have been pretty bad for PC buying.
I did an i5 based build with xfire 5850's and a x25-M back in October and now, 5 months later, the same build would cost ~$100 more. Definitely, not the sort of price change you normally see in the tech industry.