A couple tips to lower the price, but keep performance:
1) As already said, dont get the GTX. The price
erformance isnt the greatest. Perhaps, go with a 7800GT, or even a 6800GS.
2) You can save about $100 if you go with a 3700. The performance difference is marginal at most.
3)The motherboard can be downgraded a bit. If you insist on keeping SLi, then a Gigabyte mobo is a bit better on the wallet:
You could even drop SLi altogether and save even more money... If you still want to get the ASUS A8N-SLi, just make sure to get the Premium, not Deluxe. The Premium does away with the chipset fans, which are a source of frequent problems.