The United States bi-centennial half dollar was minted in between 1975 and 1976 and was in circulation as part of a commemorative set of Unite States bi-centennial coinage. The Bi-centennial Coinage Program was introduced in 1975 and seen the half dollar as well as the dollar and quarter changed in order to include the 1776-1976 dual date. There are no Bi-centennial half dollars with the 1975 date, due to the fact that the coins were struck in 1975 and 1976.
The bi-centennial half dollars are quite common as hundreds of million of bi-centennial pieces were produced. This is the reason that for the most part coinage from the Bi-centennial Coinage Program is not considered to be very valuable among collectors. However they are very popular among people that are interested in owning a part of U.S. history as they can be purchased for relatively inexpensively these days online. There are many online auctions that specialize in American coinage and have these pieces for around $1.00 to $3.50 depending on the condition. There are many different things that can affect the price of a coin, this is also true with the bi-centennial half dollars. For example, some of the things that may change the value you include, of course, the overall condition of the coins, but also whether or not the specific coin was issued as part of a set or not. All of these things can greatly affect the price of your bi-centennial half dollars and may be something you might want to consider if your are thinking about selling. However, due to the fact that the price is quite low for these coins, its pretty safe to say that you don’t have to worry about spending or selling these coins anytime soon as they aren’t going to get much coin for your coinage.