Does it generate that much?
Everywhere within 60kms of Adelaide books out for the Adelaide Test Match. Average daily crowd is around 35k. Assume tourists make up 20% and you come up with 7k tourists.
Judging from this forum which contains ardent supporters few made the trip. The reality is that for each club less than 1k can attend.
Perhaps a game at Renmark and Port Lincoln would open things up. Renmark has the nearby towns of Mildura and Berri each off which offer additional accommodation options.
There was a lot written on the benefit of event tourism around the Taylor Swift concert. The bottom line was that unless you attract international tourists there is no net national benefit. Taking that to State level you need to attract interstate visitors. The reasoning is that if the money had not been spent by locals on the event most of it would still have been spent locally on something else
On the assumption you are getting 10k interstate tourists the Govt of SA is paying $2000 per visitor.
Event figures have always been rubbery but politicians love them.
WA will pay a fortune post 2026 is my guess