Not sure if PC World/currys realise there's more than just a difference in colour in the two models of the T100 they're selling... as they've priced them the same.
£249 is the going price for the original T100 (sometimes drops a bit lower), BUT they are also offering the newer model for the same price.
The newer model (T100TA) has an Intel Z3775 processor, as opposed to the Z3740 in the original T100. On Amazon, the T100TA models go for £290-300. Or more on other sites.
So this is a pretty good at £249 -- same price the old version still sells for, and you get the snappier processor.