What is the value of 50 cent peices?

Answer 1

Depends by what you mean "valuable" coins dated 1964 and before are 90% silver and worth at least $11 (at the time of writing) in silver content. Silver half dollars dated 1965-70 are 40% silver and worth $5 in silver. Half dollars produced for circulation dated 1971-present are copper-nickel and only worth 50 cents.

There are many key dates and dates worth more than silver melt, however the list is large and so it would be easier to either ask for the key dates of a certain issue (Ex. key date walking liberty half dollars) or ask the value of a coin (1963-D Franklin Half Dollar)