Tasmania will not be considering any sports other than afl and cricket. It is a sporting dead end.High cost is partly due to being built on land partially reclaimed from the sea, like Optus in Perth. Plus the roof and moveable seats add to the cost.
They also plan to make York Park in Launceston 27,500 regardless of whether they get an AFL team. 190 page report here
https://www.launceston.tas.gov.au/f...k-park-utas-stadium-2021-11-february-2021.pdf
Naturally you would assume that the NSW govt has/will prepare similar document for public discussion before committing to any stadium upgrades. I am sure they are well underway.