Arstechnica takes a look at the numbers of Piracy
According to Ars, the 750,000 lost jobs dates back to 1986 (you read that right), and is the upper end of an estimation between "130,000 - 750,000 jobs lost."
The $200 - $250 billion lost to Piracy comes from a 1993 issue of Forbes magazine that barely mentions it and cites no sources.
Seriously, it's articles like these that make Ars Technica the site I have read the longest. This article is definitely worth a read.