The aim of this experiment was to provide makers of cut packaged salads with useful information and to help them develop suitable marketing strategies. Consumer preferences and willingness to pay for clean and cut packaged salads (baby leaves) were investigated. The focus was on the impact of more sustainable packaging on consumer preferences and willingness to pay. We conducted a multi-product fifth-price (simultaneous) auction among 302 consumers of clean and cut packaged salads (baby leaves) in Barcelona (Spain) in December 2023. The auction consisted of a total of three rounds, and in each round, respondents had to bid simultaneously for two bags of salads with the same content but with two different packages: One 100% recyclable packaging versus one 100% biodegradable packaging. To make the experiment more realistic, the test subjects were given €5 at the start. Results from a Tobit model showed that consumers are willing to pay a price premium of €0.28 for clean and cut packaged salads (baby leaves) whose plastic bag is 100% recyclable and 100% biodegradable. Moreover, consumers WTP for salads with more sustainable packaging is influenced significantly by consumers’ perception, price sensitivity and familiarity with the product in question.