I bought a new blade for my 45mm Olfa cutter a few weeks ago and paid just over £3.50. In the local sewing shop they are now £5.99 or thereabouts. So I bought one of these in Hobbycraft and I only need to sharpen three blades and the sharpener will have paid for itself. It's been tried out and the old blade it sharpened was like new. Definitely a good buy!