1965 Liberty Half Dollar value

If you really mean 1965, that is a Kennedy half dollar and would only be worth melt which at the moment is about $3.15, if you mean 1865 which would be a seated liberty half dollar the situation becomes more tricky, for one, old coins are extremely dependent on condition, do not clean the coin that is the number one killer of value when it comes to old coins like this. But it really depends on the condition and mintmark, it is certainly valuable, but how much depends on the condition. A mint-state 1865 half dollar would be worth easily over $100, however one in poor condition might only be worth $20.