This paper measures the cost of greening the economy from the customer’s perspective using nearly six million US federal procurement contracts from 2007 to 2024. Green contracts are on average 18 to 43 percent more expensive than comparable non-green contracts. Accounting for endogeneity with a Bartik instrument yields an even higher cost premium. The premium increases with public concern about climate change, declines with experience, and rises with regulatory complexity. Green contracts also involve greater administrative effort, including more modifications and delays. Overall, the green transition imposes substantial but partly transitory costs shaped by public sentiment, learning, and regulation.