I doubt he put much into that house.
Edwards sold the Georgetown house for $5.2 million (he had paid $3.8 million in 2002, so it's not a huge stretch to spend $6 million for a new house in the Chapel Hill area (although I have no idea how the tax assessment rate relates to actual value, in Virginia Beach where I live assessment is only about 70% of market value). Plus, I'm not sure whether or not he is selling his other house in North Carolina (IIRC it was in the Charlotte area, but I could be wrong), and if he is he certainly made money on it too.
And to top it all off, we don't know how much Edwards is actually PAYING for his new house. For all we know, he could have some sort of business relationship with the builder.
http://www.washingtonpost.com/wp-dyn/content/article/2007/01/18/AR2007011802077.html