These are large silver medals with almost one full troy ounce of silver. Their value depends on the price of silver and the overall condition of the medal.
To evaluate this medal, the first order of business is to figure out the value of the silver it contains. Look to web sites such as kitco to find the price in US dollars per troy ounce. Since the medal contains about one troy ounce of silver, the price of silver gives the value of the silver in the medal. At this writing, silver is trading at $14.62 US dollars per troy ounce, so the base value (BV) of the medal is BV = $14.62.
The value of the medal runs like this:
average circulated: BV + $3 US dollars
well preserved: BV + $10
fully uncirculated: BV + $25
If you have a medal with the ribbon intact and in good condition, add a few more dollars.
Of course, no amount of analysis will account for the sentimental value of the medal. The prices above are guidelines for the bare-bones item, with no sentiment attached.