Yeah, really odd math going on in that article. Counting the Borders stores alone, he says 300 stores at 12 units each - that's 3,600 units. 3,600 * 350 = $1.26 million. And that's just the Borders stores. Even if these things are wholesale at a really low price of $200 (not likely) then that's still $720,000, again from the Borders stores alone.
That's if you assume the unit counts are right. If you assume the dollar figure is right - $500,000 - then that means approximately 1,400 readers were released, not 10,000.