What I believe Fatomas is saying is that the in situ valuation already takes into account the net present value and the relative risk factors and then sets an "average" valuation. So in essence the $75.00 dollar number is the average being paid all risks and discounts factored in. From that figure you can add in a premium for the location and jurisdiction.
Perfect !
And as accurate as any "scientific discount method" with numerous uncertain variables.
FANTOMAS