Just been to Tesco superstore in BlackWater and they have these boxes on clearance at £1.25 from £5.50. Still had 15 boxes on shelf.
These ergonomically designed, extremely versatile storage boxes are manufactured from durable polypropylene and most are strong enough to take a person’s weight. Each box is supplied complete with a lockable lid for added security and protection of confidential contents. Each box includes a flat reinforced base and minimal wall taper to maximise storage capacity. They can be stacked with or without their lids and have a working temperature range of between -15°C and +80°C.