It's original price was about $16, and there are currently 42 people wanting that pin, with just one person having it for trade. I would say it's mildly popular (not insanely popular) and would make an excellent trade. If you don't want it, my recommendations would be A) Trade with it for something you do want B) Give it as a gift to someone who may like it -or- C) Sell it on ebay. I think you might get about $15-20 on it, but who knows! I definitely wouldn't toss it, would be a shame to see a pin like that go.
I'd say it's an "eh" pin. Not sure of the edition size, 7 trading, 20 wanting. There's really not much to say about this pin, other than it seems you had to earn it by volunteering. I'm sure there are still people out there that would want it.
Over all, I'd say they are nice pins, and you are lucky to have them. If you end up not keeping them, good luck finding a good home.
PS: If you are looking to sell them here, please use the trade/sell boards on MiceChat.
PPS: If you are thinking of trading them in the parks, please be aware of "sharks" who are looking to take advantage of newbies that don't know the value of a pin. Know what you are trading!