Order a machine reamer by diameter, from KBC Tools, and freehand grind (or better, use a jig) the shank end to the size and shape you want.
Or...Look under "Tool and Cutter Sharpening" Or Tool and Cutter Grinding" in the yellow pages for a cnc grinder equipped shop and talk to them about what you need. They may be able to grind what you want out of something that they have on hand.
After that, you start into the aircraft tool suppliers and cheap is a non-starter.
Cheers
Trev