Dodd, Black Milliput is currently only sold directly from England and must be purchased via UK Pounds. At least that was the case when I bought some back around March of 2003. I want to say at that Time they were charging roughly $5-6 (or was it 5-6 pounds...) per package of Black Milliput, not counting shipping.
You can always ask them directly at http://www.milliput.com
to see what the story is today.