In reply to Doug:
Bowmore is always on special offer at one of the big supermarkets, same for Jura, Highland Park, Old Pultney, Highland Park, Glenlivet, Glenfiddich, and Talisker - RRP doesn't really exist for those whiskies. You would only ever pay full price if absolutely desperate and unable to walk across town to another supermarket.
Booths and Waitrose admittedly do have some more "special" offers for Christmas - reductions on whiskies that are rarely discounted. Ardbeg, Aberlour 16 (down to £33 from £50), Laphroig QC and Ancnoc all cheap at Booths. Waitrose have Glenfarclas 12 (which I've never seen reduced before) and Glenlivet Naddurra 16 (down to £38 from around £50) amongst many others.