Answer: because the resource is not easy to get that is, scarce.
Explanation:
Resources are the things needed for normal functioning or are the things required for productivity. Resources are mostly found naturally and not not through man-made, although, there are manmade resources though in terms of capital(money). Resources can be factors of production, that is, land, entrepreneurship, capital and labour.
Also, resources can be classified as renewable resources or nonrenewable resources. Therefore, when people know the values of resource and are also willing to pay for, it is because the resource is not easy to get that is, it is scarce.
