Hello there! That's a fantastic question. Many people have these cool 1776-1976 Bicentennial Kennedy half dollars and are curious about what they're worth. While one of the provided sources didn't contain information on coin values, I can certainly help you out with this.
The value of a Bicentennial half dollar really depends on two key things: its metallic composition and its condition. Over half a billion of these coins were made for the celebration, so they are quite common.
Most of the Bicentennial halves you'd find in your pocket change are the standard "clad" versions, made of copper and nickel. These were minted in Philadelphia (which may have a 'P' mint mark or no mint mark) and Denver (with a 'D' mint mark). Because so many were made, these circulated clad coins are typically only worth their face value of 50 cents. If you have one that looks brand new and has no wear, it might be worth a few dollars to a collector.
However, there is another version you should look for. The San Francisco Mint (with an 'S' mint mark) produced special Bicentennial half dollars for collector sets that are made of 40% silver. These are always worth more than face value. Their base value is tied to the current price of silver, which usually puts them in the range of a few dollars each, with that value fluctuating. If the 40% silver coin is in pristine, proof condition, it can be worth even more to collectors.
So, to sum it up: check the mint mark! If it's a 'P' or a 'D' and looks like it's been used, it's likely worth 50 cents. If it's an 'S', you have a silver coin worth at least a few dollars.
