Check this out:
In an article about CMMI and Scrum the site ExecutiveBrief (go there at your own risk) states something like:
There is a tradeoff between cost and quality
The person who wrote that line cannot have written one single line of production code in his/her life! What a f*?€%# idiot (excuse my french, I'm sounding like @bellware).
The point is that quality software is cheaper, not more expensive than crappy software. For everybody: not just the customer, but also the vendor/developer.
When people try to sell you the idea that CMMI and Scrum are complementary they are only disguising Scrum in clothes that are easier to swallow for the gray-suited execs that don't understand software at all and should have been fired a long time ago!