Club set dilemma

The fact that you got the Adams set as a prize rather than selecting them and being fitted makes me question how "right" they may be for you.  However, I also doubt that hitting them some would change what you can sell them for at this point unless there is some sort of deal with the store that provided them for a prize to take the unused clubs back, either for cash (doubtful) or credit for something else (more likely).  But if there is no such deal, you're basically selling "used" clubs anyway.

not used they are still in wrapper with the box and shrink wrapped They were bought from amazon

My vote would be to rip off the plastic wrap and hit the range and give them a try.

http://valueguide.pga.com/detail-exec/brand/2657/b/Adams

Worst case is you now have a loaner set, or a backup set in case something happens to your primary clubs.

If you do decide to test them out then maybe follow up with some feedback to how you think they compare to whatever your 15 year old set is, how the hitting distances compare, accuracy between the two sets, forgiveness comparison, and so forth.