There is a bug in some of Google AdWords revenue reporting tools that default the earned revenue at $10 per sale.
This was first reported at WebmasterWorld yesterday afternoon.
My google reports are showing any revenue I have from each keyword as $10. We don't have any products that cost $10, so there is no way we could actually have a $10 sale. Even up to 14 conversions are being reported as $10.
AdWordsAdvisor has confirmed that "some advertisers" are seeing the same problem, but to rest assured, the problem will be fixed shortly.
AdWordsAdvisor added that "no data has been has been lost - so once the issue is resolved, you'll be able to run reports and see the correct data."
So once the issue is resolved, things will go back to normal, with no signs of a problem ever existing.
Forum discussion at WebmasterWorld.