The king's royal household gets about ZAR 71 300 000 per year [1] (EUR 3 500 000, tho I think the actual buying power is much more than the euros would indicate).

I don't know if that royal family brings in any tourism money like royals in some other countries. Hopefully not, because tourism is a major contributor to catastrophic climate change.

The South African constitution states that "A traditional authority that observes a system of customary law may function subject to any applicable legislation and customs, which includes amendments to, or repeal of, that legislation or those customs. The courts must apply customary law when that law is applicable, subject to the Constitution and any legislation that specifically deals with customary law." [2]

Traditional laws include polygamy, and the previous king had 6 wives and about 28 children. [3] The former president of South Africa, the openly corrupt Jacob Zuma, is a Zulu and had about 21 children. [4]

The Zulu king effectively owns 30% of the KwaZulu-Natal province, and that 30% is more land than the entire country of Rwanda. [3] [5]

• [1] https://www.timeslive.co.za/politics/2020-06-02-king-goodwill-zwelithinis-budget-increases-to-r713m/
• [2] https://www.gov.za/documents/notices/constitution-republic-south-africa-1996-chapter-12-traditional-leaders-07-feb
• [3] https://www.thesouthafrican.com/news/goodwill-zwelithini-five-quick-facts-about-zulu-king/
• [4] https://www.theguardian.com/world/2014/jul/29/jacob-zuma-nepotism-giving-daughter-ministry-position
• [5] https://en.wikipedia.org/wiki/List_of_countries_and_dependencies_by_area