Penrith Survival sell them, in a watertight plastic tub, £1.47 for 25, with striker on the end of the tub, and some cotton wool (anti-rattle) packing.
http://www.penrithsurvival.com/penrith_survival/55/mia/pid/52813
For a link to the page.
I have several tubs of these, in my go-bag, in my car, but would try to light a fire with a Swedish Firesteel first, saving the matches.
Actually, I just remembered, I had a huge bag of them that I had to leave behind in the USA, (went there on a military flight, came come civair), damn shame, there must have been hundreds !