<p>The former study suggests that Italian consumers are willing to pay premiums for new bio-based products but expect discounts on second-hand clothing, revealing a sustainability bias. This study adds more insights into such a bias by examining factors influencing consumers’ willingness to pay a premium for bio-based clothing and their expected discounts for second-hand items. Using Bayesian Mindsponge Framework (BMF) analytics on a dataset of 402 Italian consumers, the findings reveal that environmental concerns are positively associated with premiums for bio-based clothing, while higher income and education levels are also associated with the higher premium that consumers are willing to pay. For second-hand clothing, the preference for vintage appeal is linked to lower expected discounts. Men and younger consumers tend to expect higher discounts for second-hand clothing. By providing insights into Italian consumers’ sustainable fashion choices, this study offers implications for businesses, policymakers, and researchers aiming to promote eco-conscious consumption and sustainability in the fashion industry.</p>