While the true value of environmental goods may be captured in a one-off payment, it may be easier to add a smaller amount to a private good by means of donation and collect the total environmental value over time. For that, however we need to ensure the smaller amount of a heritage conservation donation added to a private good is adequate so that we can find retailers to participate in such fund-raising activities. We test the contingent valuation method's criterion validity by comparing their stated purchasing behavior with their actual behavior. The price increase from the addition of the donation did not affect total sales of the commodity. Adding a donation to specialized private goods may be an effective way to collect landscape and agricultural heritage conservation donations. Furthermore, our findings suggest that funds can be collected without affecting commodity sales. This approach is effective in other environmental protection activities.