Terrible temptation aren't they? I could never front up £200+ for a full bottle of a 30yo, but £10 on top of an order just as a treat, just to see why the premium prices are paid, never seems quite so bad. I had better not mention the "buy two, get £5 off" offer at the Whisky Exchange site!
With these internet off-licences, what always amazes me is the reasonableness of the P&P. I've paid £2+ to send tiny packages to friends and family, but MoM and the Whisky Exchange send huge boxes of a dozen bottles for around a fiver. That said, the P&P is always enough to encourage me to buy a load of bottles to "get my money's worth"....