Welcome to the forums, it is almost exactly the same price as building it yourself so it depends on if you are happy with the quality of the sundry parts such as case and PSU and if you want to build the PC yourself. It doesn't seem like a bad deal at all though providing the Ram and case/PSU are good quality, here is the comparison system from here to check against.
OcUK GeForce 7900 GS 256MB GDDR3 TV-Out/Dual DVI (PCI-Express) - Retail £99.99
(£117.49) £99.99
(£117.49)
Corsair 1GB DDR2 Value Select PC5300 Dual Channel Kit (2x512MB) (VS1GBKIT667D2) ( £72.99
(£85.76) £72.99
(£85.76)
Intel Core 2 DUO E6300 "LGA775 Allendale" 1.86GHz (1066FSB) - OEM £93.99
(£110.44) £93.99
(£110.44)
Creative Sound Blaster X-Fi Xtreme Music - OEM £44.50
(£52.29) £44.50
(£52.29)
Arctic Cooling Freezer 7 Pro CPU Cooler (Socket 775) £13.99
(£16.44) £13.99
(£16.44)
NEC AD5170 18x18 DVD±RW Dual Layer ReWriter (Black) - OEM £16.99
(£19.96) £16.99
(£19.96)
Antec NSK4400 Mini Tower Case - 380W SmartPower PSU £46.99
(£55.21) £46.99
(£55.21)
Samsung SpinPoint P HD160JJ 160GB SATA-II 8MB Cache - OEM £36.49
(£42.88) £36.49
(£42.88)
Asrock ConroeXFire-eSATA2 (Socket 775) PCI-Express DDR2 Motherboard £49.99
(£58.74) £49.99
(£58.74)
Microsoft Windows XP Media Centre 2005 Edition - OEM - 1Pk (M93-00200) £65.99
(£77.54) £65.99
(£77.54)
Sub Total : £541.91
Shipping cost assumes delivery to UK Mainland with:
City Link Parcel Next Day (Delivered Mon-Fri)
(This can be changed during checkout) Shipping : £10.95
Vat : £96.75
Total : £649.61
