Well, it seems the context you've provided is the digital equivalent of a book's cover and table of contents, without any of the juicy pages in between. So, let's set that aside and dive into the real story based on general numismatic knowledge.
Asking how much a Kennedy silver half dollar is worth is a bit like asking how much a car is worth; it really depends on the year and model! The Kennedy half dollar has had a few different makeovers, metallurgically speaking.
First, you have the rockstar of the series: the 1964 Kennedy half dollar. This was the first and only year the coin was struck for circulation with 90% silver. Because of this, its base value is tied directly to the fluctuating price of silver. Think of it as a small, round silver bar with a president's face on it. It will always be worth significantly more than fifty cents, typically falling in the range of several dollars just for its silver content alone.
Then, from 1965 to 1970, the U.S. Mint, feeling the pinch of rising silver prices, decided to put the coin on a diet. These half dollars are "silver-clad," containing a 40% silver composition. They're the little brother to the 1964 edition—still worth more than their face value due to that silver, but not as much as the 90% original. You're looking at a value of a few dollars each, again depending on the day's silver market.
After 1970, with the exception of special collector proofs, the party was over. Kennedy half dollars made for circulation became a copper-nickel clad sandwich, containing absolutely no silver. So, if you have one from 1971 or later, you generally have... exactly fifty cents. Enough to buy half of a dollar-store item, but probably not enough to retire on.
Of course, condition is everything. A pristine, uncirculated coin from any year will fetch a premium over a well-worn one. But for the silver-era coins you're likely to find in an old drawer, their primary value comes from that precious metal content.
