This depends on the grade and mint Mark, I have to see them. Also a full sovereign and a half sovereign they look exactly the same and so it should be weighed or measured. An uncirculated Australia sovereign of that date can retail for &400. A worn common one scraps at $250. That's your range. It was made as a bullion product and it remains the same and if it's worth more than gold that's the dealers profit and it's usually not a large margin.