sharp sand

[Rhumba]

am going to be building some rasied beds and the soil here is very heavy with clay.need to add some sharp sand but no sure what to use. B & Q do various types of sharp sand one for about £1.50 which suggests it's used for construction and one with a lovely gardeny picture for £5 - is there a difference or are they just trying to rip you off?

[MaryMotherOfCheeses]

Not sure I would do sharp sand. Have been reading this for my own purposes. Better with compost or some other organic stuff.