Sorry to say, but to most peopl it is only worth face value, unless it is a very clean uncirculated coin.
Avi, Kennedy halves are beautiful coins. If this particular one inspires you to put a set together, then it has been very valuable. I presume you like it a lot since you took the time to post the photo. One nice thing about Kennedy halves is that a set can be put together for a reasonable cost.
1971 D Kennedy's are the most common of the series with 302,097,424 minted, but as Cloudsweeper said, if its sparked your interest in the hobby, than its worth more than $0.50 Welcome to CoinTalk