Australia 1883S Half Sovereign PCGS AU55: S-3862D Cross-not-buried variety.
Equal finest example graded by PCGS. The scarcer variety from a common date year; with toothed denticles.
I have found some information from coin dealer Walter Eigner that illustrates the rarity and subsequent price of this particular date. The author has confirmed that these pages devoted to half sovereigns are a work in progress. So the information (pricing above all) should prove of some use for interested collectors.
http://numistip.com/Museum/1883-S_Crenulated_Reverse_Half_Sovereign_598.html
The certificate for this coin can be verified by clicking on the button below (opens in new tab):
