Although many supporters will fly over for the three-match Test series and not the provincial matches, the majority of that huge number are expected to stay in South Africa for at least three weeks.
The size of the last Lions tour to New Zealand four years ago has prompted the positive analysis from the SARU who believe that at least R250 million will come from direct foreign exchange revenue.
That figure would make the 2009 Lions tour the biggest international sporting event ever hosted by South Africa.
"The Lions contributed direct foreign exchange of R720 million (to the New Zealand economy in 2005)," the tour's project manager Andre Homan of the SARU explained to www.sagoodnews.co.za.
"And there was a total GDP impact of R750 million. So we can safely say with the numbers that we're expecting, that we'll top R1 billion in direct earnings very easily and that is hard currency earnings."