Since the recent price hike from Canon the cheapest UK price I've seen for this lens is now around £210.
This is a great lens for the price and it has a UD lens and built in Image Stabilisation for use with Canon xxD/xxxD/xxxD Digital SLR bodies.
There are a couple of Grey Importers selling this lens for around this price but these are not covered under Canon UK warranty but only a return to base warranty.
They are only available in store and you can reserve Online if they have stocks. When I phoned Comet, they mentioned that it's discontinued but I believe this information is incorrect as it was only launched last year! Perhaps they are going to stop stocking this item?
I also managed to get an extra 10% off as they only had the display lens left, which they informed me was only put into the cabinet last week and no one has handled it.