I have a hard time understanding how a guy who builds computers for others wouldn't know what is a good price for a CPU is and what to get.
OK, for business applications and multitasking (on a single core), the Intels often do well.
But for anyone gaming, for the love of "SpongeBob", please check this out...
http://www23.tomshardware.com
BTW, after doing some research, I LOOOOVE the Zalman 7000 series heatsinks and the Coolermaster LED case fans. That will make your customer's machines silent (and a power supply like Antec Phantom).
There are presently 3 Athlon 64 3400+ 2.4 GHz left at compuvest. Even though it's only a socket 754 (in other words, not upgradeable to dual core), I ordered one since it's kick ass fast. I also ordered Corsair CAS2 RAM, Asus K8N4-E Deluxe and a X700Pro (on sale at tigerdirect.ca for $135 CDN). Yeah, I know it's less powerful than the 6600 GT but I only like Unreal Tournament 2004.
So, I saved like over $70 CDN on that one and don't lose that much performance-wise with that card in that game.
http://www.xbitlabs.com/articles/video/display/2004-27gpu2.html
Now, that's a great link with a large array of benchmarks...