The AMP version is pre overcloked, hence faster than the non AMP version and is £40 cheaper.
That doesn't make any sense business wise lol. 700/1700/2000 is a good oc and u will still be covered by the warranty at those speeds.
After a quick search the cheapest 8800GT 512mb I could find was £100 for a Club 3D @ stock speeds, so £5 more for a pre overclocked version is good.
The 8800GTS 512mb is the card up from the 8800GT 512mb and the cheapest I can find that is £137.63 + p&p for a Zotac 8800GTS 512mb AMP Edition
(only a quick search).
DFI LP X48 LT T2R | Bios 12/24 | XSPC Delta Chipset
Intel Q9550 E0 @ 3.6ghz (424 x 8.5) | Swiftech GTZ
OCZ PC2-9200 4GB (2 x 2G
Flex II @ 1121mhz 5-5-5-15 2T
2 x Sapphire 4870 1GB @ 780/4000
Auzentech Forte 7.1
3 x DGM 24" L2442W-VA LCD
3 x WD 150GB Raptor (Raid 0) & 2 x Samsung F3 1TB (Raid 1)
2 x NEC DVD Writers
Enermax Modu82+ 625W
Custom Water Cooling
Windows 7 Home Premium 64 Bit