If you mean Burdall's Gravy Salt, I believe it was a victim of the foot-and-mouth outbreak a few years back, and had to be discontinued because of it's use of bone marrow, or something. Pity.
Just got back from Morrisons and they sell Comptons gravy salt @ 42p for 128grams, don't know if that will do for you but at least you know about it now.