Should I set it up? How? Or should I leave it in the box as a collector's item?
Build a small throne for it and worship it. Surround it with candles and some used iTunes cards. Steve will love you.
How old is it?
Nope, totally real R1 (good for being bitchy!) "Just Feel Better" by Santana is the song being advertised on the ever so earnest packaging. So, leave it in the box or put it in my car?
Use it if you want. No one is going to want to buy it for good money as a "collector's item" or care.
My mommy says you should always return things found to the proper owner.
You should start by taking out ads in the local paper, on Craigslist and put signs up around the neighborhood.
Then after two weeks, turn it over to the local police.