How much is a marine security force coin worth with white house communications agency on one side and number 015 on the other side?

Depends on how bad someone wants it. To some it may carry more sentimental value than what it is truly worth. It also depends on the coin, is it a reproduction from a site like challengecoin.com or is it a coin that was passed out by WHCA staff? How did you come to posses the challenge coin? I would guess you could get somewhere between $5 to $50 on a good day.

I may be interested if selling it.My email is iacoman2002@Yahoo.com put challengecoin in subject. I was assigned to that unit MSF WHCA.