I know you are trying to pin a value on the ecosystem, or something like that, but that's also not something that is quantifiable. It's waaaaay tooooo vaaaaague.
It is not.
You should think about the human species with a historical perspective. More than 2000 thousands years ago, Brazilian lands were already populated by native tribes. They recognized wealth in the biodiversity of the environment where they lived. E.g. if a native male were able to fish a great quantity of fish, he would be a wealth man. If a tribe could obtain a great quantity of manioc, they would be a wealth tribe. The tribes lived for many years attacking each other regarding the quantity of wealth held by each. Of course this is not the only reason for the attacks. This serves to illustrate that wealth was recognized in the biodiversity before the human specie develop complex economic models.
Another interesting example is the Brazilian Atlantic forest, which was almost destroyed by the economic progress and urbanization. What was left is protected by the state. If the state did not interfered, this peculiar kind of forest which is only located in Brazilian east coast would not exist anymore. All the potential wealth which could be obtained from that biodiversity would vanish forever. This would be catastrophic for the Brazilian ecosystem. The Atlantic forest holds a rich diversity of fauna and flora which cannot be reproduced anywhere in the world.
I recommend this article if you want to learn more about the Atlantic forest:
http://whc.unesco.org/en/list/893The 25 Atlantic Forest South-East Reserves contain some of the best and most extensive examples of remaining Atlantic forest in Brazil displaying the biological wealth and evolutionary history of the one of the world's richest and most endangered habitats. From mountains covered by dense forests, down to wetlands, coastal islands with isolated mountains and dunes, the area comprises a rich natural environment of great scenic beauty.
Partially isolated since the Ice Age, the Atlantic forests have evolved into a complex ecosystem with exceptionally high endemism (70% of the tree species, 85% of the primates and 39% of the mammals) and are considered to be among the world's richest forests for tree species.