The author would likely describe the idea that "we can persuade people to save nature by making it possible for them to sell it" as:
a fallacy, because if people’s motivation is money, they might sometimes choose money over preserving nature.
In the passage, the author expresses skepticism about the effectiveness of monetizing natural services as a conservation strategy. They highlight the danger of prioritizing monetary value over the intrinsic value of nature, suggesting that this motivation could ultimately lead to its destruction rather than preservation.