This is probably about as cheap as you can do it new for AMD, interestingly an A64 AM2 chip is cheaper than the Sempron AM2.
CP-162-AM AMD Athlon 64 3000+ 1.80GHz (Socket AM2) - Retail (CP-162-AM)
£44.99 £44.99
MB-149-AS Asus M2NPV-MX (Socket AM2) PCI-Express DDR2 Motherboard (MB-149-AS)
£44.99 £44.99
MY-012-GS G.Skill 2GB DDR2 LA PC2-5400 (2x1GB) CAS4 Dual Channel Kit (F2-5400PHU2-2GBLA) (MY-012-GS)
£124.99 £124.99
HD-023-SA Samsung SpinPoint P HD080HJ 80GB SATA-II 8MB Cache - OEM (HD-023-SA)
£25.95 £25.95
CD-020-SO Sony DDU-1615 DVD-ROM (Black) - OEM (CD-020-SO)
£10.50 £10.50
CA-004-AS Asus TA-210 Series Midi Tower (Black) - 360W PSU (CA-004-AS)
£32.00 £32.00
Subtotal £283.42
Shipping (City Link Parcel Next Day (Delivered Mon-Fri)) £9.95
VAT £51.34
Total £344.71
Or maybe a Celeron D based system like this but you only save ~£25 for a far inferior CPU.
MY-012-GS G.Skill 2GB DDR2 LA PC2-5400 (2x1GB) CAS4 Dual Channel Kit (F2-5400PHU2-2GBLA) (MY-012-GS)
£124.99 £124.99
HD-023-SA Samsung SpinPoint P HD080HJ 80GB SATA-II 8MB Cache - OEM (HD-023-SA)
£25.95 £25.95
CD-020-SO Sony DDU-1615 DVD-ROM (Black) - OEM (CD-020-SO)
£10.50 £10.50
CA-004-AS Asus TA-210 Series Midi Tower (Black) - 360W PSU (CA-004-AS)
£32.00 £32.00
CP-117-IN Intel Celeron D 326 2.53GHz (LGA775) - Retail (CP-117-IN)
£24.99 £24.99
MB-004-AK Asrock Conroe945G-DVI (Socket 775) PCI-Express DDR2 Motherboard (MB-004-AK)
£45.99 £45.99
Subtotal £264.42
Shipping (City Link Parcel Next Day (Delivered Mon-Fri)) £9.95
VAT £48.02
Total £322.39
//edit, maybe wait a little while to find some cheaper memory as OcUK seems to have sold out of the cheaper stuff.
