I was in my local Tesco's last night (Glossop) and noticed that the Lego Star Wars V-19 Torrent set had been reduced by about £12 from £49.99 to £37.97 - so something like a 24% reduction which doesn't seem too shabby. There were 2 on the shelf.
Store specific? Who knows?!! But Glossop isn't that big a store so it might be worth checking your locals if it's something you're interested in.