They have got them online; £4.99 for a pack of 40.
I'd never heard of them but they look great (any excuse to go to Lakeland and spend a fortune): "Produced from real butter, Butter Buds undergo a special process that removes the fat and water leaving behind just the original buttery taste. When sprinkled over hot potatoes, vegetables, pasta or rice, they'll butter you up... but, containing only 10 calories per sachet, not your waistline!"