The importance of aquaculture in reducing pressure on wild stocks in the seas and meeting the demand for fish worldwide has increased greatly in recent years. However, sustainability of the sector can be jeopardized by the incessant use of fish meal as the main source of feed. For this reason, replacing, even partially, fish meal with other feeds such as insect meal is essential to make this sector more sustainable. However, this transition requires consumer acceptance of this innovation, which comes through price, one of the most powerful marketing tools affecting the evaluation of product alternatives (e.g., fish fed with traditional feed or insects) and the final purchase decision. The objective of this study is to explore the acceptable price and the limits of price thresholds of fish fed with insect meal using a direct measure of assessing consumers’ willingness to pay. In particular, the study uses the Price Sensitivity Meter (PSM) of Van Westendorp to evaluate the reaction of Italian consumers to the price of European sea bass (Dicentrarchus labrax) hypothetically fed with insect meal. The results showed a wide acceptable price range, an indifferent price point very close to the price of traditionally fed fish, and a high price stress factor. Consumers have shown considerable price sensitivity, which does not allow the additional costs arising from the use of this sustainable alternative feed to be passed on to them. Consumers with great subject knowledge showed major willingness to pay. The contribution of our study lies in providing detailed insights into the possible prices that consumers are willing to pay for sea bass fed with insect meal and thus on the product’s perceived quality, offering several implications for academics, practitioners, and policymakers.