Women and ethnic minorities (e.g., Latinos) continue to be underrepresented in science, technology, engineering, and mathematics (STEM). In an attempt to understand why these STEM minorities are underrepresented, we explored high school students' cost perceptions about pursuing STEM in college. Past research has grouped cost into three dimensions: effort, loss of valued alternatives (LoVA), and emotional. Focus group interviews with Latino high school students confirmed the three cost dimensions, but there were some cultural sources of cost unique to our sample. Consequently, we modified and refined existing cost items to create a STEM-specific and culturally contextualized cost scale. We utilized our scale to examine how high school students at the intersection of gender, ethnicity, and math identification differ in cost perceptions. Results showed that high, compared with low, math-identified students had lower effort and LoVA costs. Among high math-identified students, we also found that STEM ethnic minorities had lower emotional cost than STEM ethnic majorities.