I wrote a really long post for this but then my browser crashed so I lost the details. Basically until Monday Waterstone's are offering the newly released and well reviewed Sony PRS-350 for £129.
Waterstone's are also participating in the Sony VAT back campaign. If you go in store then the claim forms are next to the e-book readers. Once the VAT is claimed back it should bring the price down to £106
The price is instore only, the price on the website is £159. I checked the price ticket and confirmed with a member of staff that the lower price is available until monday, so if you want this be quick.