This wouldn't cost Â£160
http://www.cclonline.com/product-info.a ... id=mbb0015
Or this lot from Ebuyer, with free delivery:
1 MSI K9N6PGM2-V Socket AM2+ GeForce 6100 onboard VGA 8 channel audio mATX Motherboard 148025 329 in stock Â£35.80
1 AMD Athlon 64 LE-1640 2.6GHz Energy Efficient Socket AM2 1MB L2 Cache Retail Boxed Processor 160949 236 in stock Â£29.90
1 OCZ 1GB DDR2 667MHz/PC2-5400 Memory Unbuffered CL5(5-5-5-15) 1.8V LIFETIME WARRANTY 105972 54 in stock Â£10.00
Cart total inc vat: Â£75.70
Something like that with a decent PSU would be able idle at less than 40W, but then there are all those extra HDDs...