Importance of Six Sigma/Six Sigma Lean Certification

I'm really interested in a career change to Project Management, likely an Implementation Consultant to start off with. In many of the postings I've seen, Six Sigma is listed as a preferred qualification for the positions. I know this is a cornerstone of Project Management for many organizations. However, training and certification is typically between $1500 - $3000. Does anyone have experience in how much of a leg up the certification actually provides you over the competition? I'm interested in learning, but that's a significant amount of money to invest, especially if it's a bit of a non-issue.