Just reading a magazine article about the ODA issue.
I found this interesting: ".......the percentage of work delegated to the ODA's - measured in certification plans and deliverables within each plan - routinely tops 90% and has for years. The FAA estimated that more than 95% of certification work on the 747-400 program was delegated, a 1993 US government report said."
A different article regarding certification costs said: "The certifications costs alone on a small business jet or a small regional aircraft programs runs about $10 million per month, while larger model aircraft can cost four times that amount."
$40 million per month.