Although in the main not Warhammer related, both Darksphere stores have removed a load of stock from their website and are selling them at a discount in store in order to clear it. This includes a lot of their Warhammer/40k/heresy novels at 25% off. (They posted this on their FB page).
As this store gives about the biggest discount off products in the UK (at least on GW’s range), this could potentially give you a big saving in these ranges. No idea how much stock is available but it was posted yesterday so I’d get down early to make the most of it.