We tested the hypothesis that high costs of living, such as from high housing rents, reduce the healthfulness of food acquisitions. Using the National Household Food Acquisition and Purchase Survey (2012-13), we examined the relationships between cost of living and food acquisition patterns among both SNAP participants and non-participants (N = 5,414 individuals from households participating in SNAP, 3,863 individuals from non-participating households <185% of the federal poverty threshold, and 5,036 individuals from non-participating households >185% of the federal poverty threshold). Indices for cost of living included county-level Regional Price Parities for major classes of expenditures and the geographic adjustment to the Supplemental Poverty Measure, which is based on rent prices. We regressed the cost of living indices against measures of food acquisitions per person per day in each of several standard food categories, controlling for individual-, household-, and county-level characteristics. Using endogenous treatment effects models to potentially address unmeasured confounders influencing both the propensity to live in high-cost areas and patterns of food acquisition, we observed that higher area-level costs of living were associated with less healthy food acquisitions, including significantly fewer acquisitions of vegetables, fruits, and whole grains, and significantly greater acquisitions of refined grains, fats and oils, and added sugars. Overall, living in a high-cost area was associated with an 11% reduction in the Healthy Eating Index—a composite nutritional index previously associated with obesity, type II diabetes, and all-cause mortality. Additionally, we found that SNAP participation was associated with a significantly improvement in the healthfulness of food acquisitions among persons living in high-cost counties.