To get this price you need to apply 10% dicount code (thanks to Mike T) GLTV1QH8DCMLWF at checkout. You also need to go through Dell Business (when asked for a business name do not make one up just supply your normal name as I believe this can affect the warrenty slightly. After clicking on link select the 256mb card, you will then get a compatibility message. Just click on the fix graphics link and select the higher 90w power supply that is needed to power the dedicated graphics accelorator.
This is my first post and as it is cheaper than the Vostro 1510 listed with Intel X3100 graphics (listed at £316.19). So you get a superior dedicated graphics upgrade at a better price. Worth a mention in my mind.
With the additional 5% Quidco you could get this for £298.39 a real bargain.