I don't work for any developers so my opinion may not be correct but they will be unbiased.

I would consult an unbiased 3rd party such as a CPA.  

I'm simply trying to offer an unbiased opinion to @Enrique S. based on my personal experience, that's all.

I don't live in those markets and I don't trust media reports to be unbiased.  

Any unbiased opinions or insights?

The reason homeowners hire Structural Engineers is because they believe that is their only option for an unbiased opinion of their foundation.

This will help to ensure that there is an unbiased third party valuation of the property.

Ethically it would be reasonable to bring another agent in from your firm, or even another firm, to witness discussions and provide an unbiased opinion on what the seller could reasonably expect to get if he lists it on the MLS - that turns you into just a buyer if he doesn't want to list it, and the listing agent if he does want to list it after hearing his realistic options from a disinterested party. 

An agreement made beforehand is always more unbiased than trying to come up with a fair buy-out in the future right?

Perhaps a nice 1950's built bungalow.Always hire a 3rd party property inspector to give you an unbiased feel for the home.