Tesco Direct are having 3 for 2 on all toys until Sunday 12th December.  Sadly, it seems the little reductions on sets have gone whilst this deal is in operation, but you can’t have everything.  Save on delivery by having them sent to your local store for free.  Mind you, spend over £50 and you get free delivery anyway!  Stock also seems to be a bit of an issue too.  The specific Lego section is here.