But that doesn't mean that it's going to be valued by the market. If it's not valued by the market, the fact that it's rare doesn't help you. For a high market

But that doesn't mean that it's going to be valued by the market. If it's not valued by the market, the fact that it's rare doesn't help you. For a high market price, you need the intersection of a scarce skill (low-supply in labor market) that provides value to other people (high-demand in the labor market). Being a good software engineer is an example - low-supply and high-demand, therefore high wage/salary.