i got 2!
£1 each both unused from army surplus shops they were the only ones!
i used to work in "scouts shops" and we sold a milbank/iodine set for £15!
personally i think £15 is alot to ask for a bit of canvas and iodine!
there are alot of these going around and you will find them fairly cheap 2nd hand, obviously wash them well before personal use.
incidentally those springfield millbank bags look used and for £9!
it's canvas, if you really want one make one! for penny's!
my tip is to always rummage in surplus shops you will always find agem!