Haven't seen this on HUKD and couldn't find it when searching for previous posts. Think its a great price with an RRP of £49.99 who can argue at £17.99.
You will be able to get this even cheaper using quidco and the RAC voucher attached. Effectively you could get it for £16 delivered if you use the voucher and quidco tracks.
They have all sizes in stock. People who have reviewed this on play.com recommend buying the next size up as it is a bit of a tight fit from the sounds of it.
Please state reason if you decide to vote cold. Thanks.