Ouch, HVM2! Since your coin is bent with nicks or gouges, it will be worth essentially zero. See if you can find another undamaged example of this old US coin denomination. Half dimes circulated until 1873, 7 years after the first five cent 'nickel' was introduced in 1866.
Collectors actively seek US half dimes to add to their 'obsolete coins' collections along with 2 cent, 3 cent, and 20 cent pieces which have long gone by the wayside.
Catalog values for US half dimes run like this:
worn: $15 US dollars approximate catalog value
average circulated: $35
well preserved: $80
fully uncirculated: $200
The coin in the photograph comes from eBay seller V B Coins and is almost or fully uncirculated.
Be sure you understand what 'catalog value' means. It is an inflated value, but it is related to the actual buying and selling values by certain guidelines. Review our Terminology page for a detailed explanation.
There are *better date* half dimes which carry values above the *common date* coins. The better dates are listed below. If you do not have one of these, your coin is of common date and worth the values in the prior paragraph. The values given for the better dates are catalog values for coins in worn condition. The values are much higher for coins in average circulated condition. Be sure to check for mint marks under the wreath on the HALF DIME side.
1853O: $180 unless arrows appear at the date, in which case it is a common date coin
1863: $160 must not have mint mark, common date otherwise
1864: $325 must not have mint mark, common date otherwise
1865: $320 must not have mint mark, common date otherwise
1866: $450 must not have mint mark, common date otherwise