I make my own. Start with an allen wrench. Grind and file to shape,
temper/quench, scary sharp, and good to go.

I use a plumbers torch for a heat source, and it takes about an hour start to
finish.

the advantage of using allen wrenches is that it makes it easy to make a blade
of a particular size (when you pick your wrench, make sure that the flats are
parallel to the bend in the wrench)..

-James