I just spent way too long getting a CSV file formatted in such a way that Google Play's bulk in-app-purchase import would be happy about it. In theory this is easy, but Google Play's example formatting is not so great. Since I couldn't find a nice simple example template, I figured I'd provide one here.
Here's an XLS file, and here's a CSV. I exported as UTF-8, with all text fields quoted, commas separating.
Also, don't forget: Descriptions can't be longer than 80 characters!