A strict gluten-free diet is the only treatment for coeliac disease, yet many commercially available gluten-free foods remain nutritionally controversial and economically inaccessible. We assessed whether the nutritional disadvantages of packaged gluten-free foods are consistent across categories and whether higher prices remain a persistent barrier to access. Data were drawn from two complementary cross-sectional surveys conducted in 2022 in three large supermarkets in Pelotas, southern Brazil. Categories included biscuits/cookies, snacks, chocolate/cereal/protein bars, beverages, yoghurts and dairy products, pasta, breakfast cereals, pastry products, and frozen foods. Nutritional values from food labels were standardised per 100 g, and price per 100 g was recorded. Gluten-free foods were compared with similar gluten-containing products within each category using the Mann–Whitney test. Nutritional differences varied by category rather than following a single consistent pattern. Gluten-free products showed lower protein content in biscuits/cookies, pasta, and pastry products, but higher energy or carbohydrate values in breakfast cereals and some yoghurts and dairy products. Sodium and saturated fat also differed according to category. In contrast, price differences were consistently higher. Gluten-free products were more expensive in several categories, including pasta (300%), biscuits/cookies (260%), snacks (152%), bars (109%), and pastry products (42%). These findings suggest that the main disadvantage of commercial gluten-free foods is not a single universal nutritional pattern, but a combination of category-specific nutritional imbalances and persistently higher prices. Improving access to a nutritionally adequate and financially sustainable gluten-free diet should be a priority for both public health and the food market.