Bhutan has the world's most expensive tourist visa, not due to a traditional fee, but a Sustainable Development Fee (SDF) of USD 100 per night. This policy, part of Bhutan's "high value, low volume" tourism model, funds crucial national services and environmental preservation, ensuring mindful travel.Bhutan has the world's most expensive tourist visa, not due to a traditional fee, but a Sustainable Development Fee (SDF) of USD 100 per night. This policy, part of Bhutan's "high value, low volume" tourism model, funds crucial national services and environmental preservation, ensuring mindful travel.