ROI for secure software engineering

Hello

I am looking for methods to calculate return on investment in secure software engineering practices. Since it is impossible to create absolutely secure software (let alone define what is absolutely secure) it would be good to know how much to spend for developer education, code reviews and so on, to reach some kind of break-even point.

I found many sites on the net which cover ROI to the application security, but none dedicated to the finance of the secure software engineering. If you know some links, please, share your knowledge.

Thanks

-- 
 Artem Frolov