<p>Reducing the use of disposable products is essential for achieving sustainable development goals. While previous studies have explored how willingness to pay (WTP) a green premium and environmental concern influence pro-environmental behavior, few have examined how these two factors interact. This study introduces a dual-dimensional framework of green premiums, distinguishing between explicit premiums (monetary costs, such as paying more for eco-friendly products) and implicit premiums (non-monetary costs, such as time and effort invested in using sustainable alternatives), to examine whether these two fundamentally different types of premiums have distinct impacts on disposables usage. It further investigates how environmental concern moderates the impact of these two types of WTP on disposable product usage. An online survey was conducted in China, yielding 667 valid responses. The results show that WTP an implicit premium significantly reduces disposables usage, and this effect remains consistent across most levels of environmental concern. In contrast, WTP an explicit premium only significantly reduces disposables usage among individuals with high environmental concern, indicating a moderating effect. These findings clarify the boundary conditions under which WTP for sustainability translates into action and emphasize the role of internalized environmental values in strengthening pro-environmental intentions.</p>