The value of a Mercury Head dime 1917 depends on a number of factors, including the coin's condition and rarity. In general, Mercury Head dimes in good condition are worth around $1. However, some rare varieties of the coin can be worth much more. For example, the 1916-D Mercury Head dime, which is the first year of issue for the coin, is worth around $100 in good condition.
If you have a Mercury Head dime 1917, you can determine its value by examining the coin's condition and checking its rarity. You can also get the coin appraised by a professional coin dealer.