As AW said the prices wont drop soon. But whats your max price? And what are you going for? A full system (every thing needed) or do you have some parts you want to reuse?

This is what I would recommend for a cheap and fast pc.

Case: COOLER MASTER RC-690-KKN1-GP ATX Mid Tower Computer Case $80
xtra fans:Scythe "ULTRA KAZE" 120mm Case Fan$10x3=30
CPU:AMD Athlon 64 X2 6400+ Windsor 3.2GHz$176
Cooler:ZEROtherm BTF90 92mm Silent UFO CPU Cooler $30
Mobo: ASUS M3A AM2+/AM2 AMD 770 AT $100
HD1:Seagate Barracuda 250GB 7200 RPM SATA-300 x2$140
Videocard:XFX GeForce 8600GTXXX 256MB 128-bit GDDR3 PCI Express x16$105-30=$74
CD\DVD:SAMSUNG 20X DVD±R DVD Burner Black SATA $30
Floppy:SAMSUNG Black 1.44MB 3.5" Internal Floppy Drive$7
PSU:COOLER MASTER Real Power ProATX 650W$140
Total: $810 (ok not as cheap as I thought it would be, but all of this could be changed , I dont know your needs, but this is what I would get)

This is chagable to what you like/need.
Moniter*: SAMSUNG 941BW Black 19" 4ms$210
keyboard/mouse:Microsoft Comfort Curve 2000 Black USB Ergonomics Keyboard Mouse Included$22


To get this better we would need to know what you need/like/can afford.

I wouldnt recommend that particular AMD processor. If hes going to go AMD, go with the +5000 black edition with the brisbane core. Also that motherboard isnt terribly great. Go with the Gigabyte AMD 690G board But i still recommend my previous build up above as the best choice for your budget range

The mobo is fine, Its even future proof, when some good AM2+'s come out he can upgrade.
Your cpu does use less energy but its only 2.6Ghz, thats .6Ghz less per core, 1.2Ghz less in total. so.. the 6400 is better imo.

The motherboard is not a very good one, from what i have read. Also, my personal preference is to Gigabyte, and i dont like ASUS as much. (this has nothing to do with it but the board also looks ugly with that tan color =P Lol) As to the processor, the +5000 is $75 cheaper, and by simply raising the multiplier (which is unlocked) up a notch in the BIOS, you get 3Ghz, which is plenty fast. Not to mention it is 65nm Brisbane core, which runs much cooler than the 90nm Windsor Core. The 6400 runs very hot and uses alot of power from what i have seen and read. Its not worth the $75 extra dollars. Im still going to stand by from given what information he has, that the Intel board would be better suited, and more future proofed.

EDIT> Not to mention the E8400 wolfdale is far more powerful than the +6400, runs cooler (45nm process) and has 4mb of L2 cache

Thanks everyone for reply.
I decided reuse some stuffs that I already have to save some money.
These are the things that I have that I'm going to reuse:
1. Cooler Master (STC-T01-UW) STACKER w/o PS SIL/BLK
2. ST3500630AS (500 GB, 7200 RPM, SATA-II)
3. Maxtor 6L200M0 (200 GB, 7200 RPM, SATA)
4. Microsoft Wireless Laser Mouse 8000 (IntelliPoint)
5. Microsoft Wireless Entertainment Keyboard 7000 (IntelliType Pro)
6. Microsoft Remote & Receiver for XP Media Center OEM
7. Plextor PX-716SA Optical Drive (SATA)
And these are the thing that I first time decided to buy (But bot fully decided what to buy):
1. 45nm Dual core CPU/Intel Core 2 Duo E8400 or better (If I buy Intel CPU)
2. Motherboard that has P35, X38 or above chipset (If I buy Intel one)
3. EVGA Geforce 8800 GTS (G92) 512MB 256-bit GDDR3
4. Either Blu-ray/HD Combo Player, Blu-ray Bunter/HD Play Combo or etc...
These are my currnent thinking.
If I decide other stuffs, I willl post them.