Computer Security Strength & Risk

Previously on this blog I have related to an ongoing discussion on risk analysis with FAIR. Also related to this problem is this doctoral dissertation at Harvard university from 2004:

http://citeseer.ist.psu.edu/631841.html

In this dissertation the author suggests an economical model to measure security of a software product. By deriving an upper and lower the bound for the price for finding a new vulnerability he is able to set a value of a vulnerability and a higher value means a more secure product.

My questions are: Has anybody implemented ideas similar to this? What do you think of such an approach?