A Dutch tech-website publishes a "Best-Buy-Guide" every two months, I've taken the liberty of translating the January edition for you.
I've also added comments based on my experiences and my system:
Processor: AMD Athlon 64 X2 3800+ € 121,83 (I compile PS on an "X1" 3200+)
Motherboard: MSI K9N Neo-F € 61,50
Memory: 512MB x 2 (1GB) PC5400 DDR2, CL4 (Corsair) € 100,16 (Use 2 GB when you start to use 3D devving tools, 1 is enough for MSVC and games)
Graphics Card: Asus GeForce 7300 GT Silent € 77,49 (Enough if you focus on playing PS, good for other games too)
Hard Disk: Hitachi Deskstar T7K250, 160GB € 53,53 (I'd prefer a 250+ GB HD, depends on how much you install and download)
DVD-Burner: Samsung SH-S182M 18x € 25,-
Case: Antec NSK4400 € 67,88
Monitor: Acer AL1916WAs € 179,10 (Good, but I personally recommend the Samsung Syncmaster (7/9)30BF series. Karyuu uses it too

)
Speakers: Logitech S200 € 15,56
Keyboard: Logitech Cordless Desktop LX300 € 41,42 (Personally I hate cordless because of batteries, I have a basic corded set and a MX510 mouse myself)
Total Price: € 743,47 (All black is usually a bit more expensive, some shops can be more expensive, and you have to account for shipment costs)
My estimate: €800,-
edit:
-You do NOT need Nvidia Toolkit to compile PS.
-Particle issues are mostly fixed with latest driver & decent (new) card. Some Nvidia related issues were also fixed in CS, but aren't in PS yet.
-Ati's "SLI" is called CrossFire.