https://www.australian-coins.com/silver-calculator/australian-silver-coin-values/ This link might help *will give you spot price not actual market value though.
Best to ask in the price check thread my man. https://www.silverstackers.com/forums/index.php?threads/the-price-check-thread.68073/
It could have some sort of added value over the silver weight depending on if it's a key year, and what sort of condition it's in. do you have a photo?