What is the value of a rare 1945 gold walking liberty half dollar with diamond?

Answer 1

It's not gold, just gold plated, so it's not all that rare. The US never made any gold half dollars because at the time a gold coin that size would have been worth about $35, not 50 cents.

Based on the diamond, my guess is that it was once part of a pendant or locket, which is why the coin was plated. The underlying silver is probably worth $5-7 depending on the coin's condition before plating. The diamond would require in-person evaluation by a jeweller to determine its value.