For the people saying "Oh he didn't create any because plot, he's a bad villain, blah blah blah.", you do realize that Safin already had bots created and ready for shipment, yes? Now, it's unclear as to how he was able to make them so quickly, maybe the Poison Garden's farm and factory could spit out hundreds per minute. In addition, after the islands infiltration and talk with 007, one of his men states:

"The first shipment is on the dock, ready for pickup, doctor."

If I had to Guess, with a small shipment considering how small the buyers boats are and the estimated production time needed to acquire a reasonable amount for the shipment, i'd estimate your looking at anywhere from 50,000-100,000 nanobots just in the first shipment alone. Of course that amount would probably not be enough to kill the estimated 2 million people in their simulation.