BPM to alert on excessive value in Credit Memo

Anyone have an idea on how to notify (or send email) when a credit memo passes a certain dollar value?
We use an automated system that takes documents from our web site and automatically creates credit memo’s for customer rebates. Management would like to be notified whenever one is created that is greater than a certain value. I can identify the creation of credit memo’s, but I don’t seem to be able to determine the value of the finished Credit Memo with a BPM.

Use routing on the report style?

When x.column > 2000 then send an email.