Please post the specs they quoted you for that price, so we can help you see that it probably is not such a good deal.
I just followed the link from the first post, and for £305.89 you can get a 21.5" screen, 1.8GHz Atom CPU and 2GB RAM. I don't think that's unreasonable (at work we tend to get Acer Revos of a similar spec - I think the last one I ordered was around £250 plus the cost of the monitor.)
