Just seen this in my local Wilko's. I have no idea if it actually was £40, but most of their garden stuff seems to be half price.
They also have BBQs from £10 (were £20) and many other garden/camping items half price, including:
- Lawn weed & seed
- Shed & fence treatments (Cuprinol Duck's Back, for example is £7)
- Bug killers (ant, cockroach, etc - all types, including powders, sprays and pellets)
- Plant and flower seeds