There is a company in the next unit to me who sharpen drill bits for the circiut board industry. That is all they do, sit at a specialist machine all day and look through an electro microscope whilst the machine pushes and pulls the bits over a big sharpening wheel. I have asker them if they could sharpen blades but they reckoned that the blades would lose thier temper and it would cost too much to set up the machine.
Its pretty interesting stuff they do, some of the bits are so small you can barely make out the grooves on the sides. They can sharpen bits down to microns in width not mm.
They charge as little as 12p each to sharpen a bit and apply a new collar to identify the length, age etc.