Over the past two decades, support for Eurosceptic parties has climbed from fringe to nearly one-third of voters. Promising renewed prosperity through less European integration, these parties imply Euroscepticism is a 'free lunch.' Drawing on an original panel of 1,166 European NUTS-3 regions (2004-2023) and using fixed-, random-effects, and difference-in-differences designs, we test how rising Euroscepticism connects with regional economic and demographic outcomes. We track GDP per capita, productivity, employment, and population growth. We find that a region 10 points more Eurosceptic than another could have ended up with GDP per capita roughly 5% lower than the less Eurosceptic region, as the negative economic influence of Euroscepticism compounds across cycles and intensified after the financial and austerity crises. The same applies for productivity and employment. Demographic impacts are smaller but point in the same direction. Even without governing, Eurosceptic support appears to deter investment and raise uncertainty, deepening the very stagnation that fuels discontent. There is no free lunch: political backlash against European integration carries measurable costs for the regions that embrace it.