Species should be protected at any economic cost?

This is an extreme position. It is, however, simpler when you compare it to the current system, where you need to do a cost-benefit analysis. Costs are easy. Benefits are hard to calculate in any meaningful way. What are the benefits of a rainbow in dollars and cents? What about whooping cranes?

Money is created by man. It can be produced again and again if necessary. Man cannot create life. So, life is much more important than money. Extinction of even one species can bring disastrous imbalance in ecosystem which will then be impossible to stop even if we spend everything we have.