Most pins have dropped in value. The two pins in this series are examples of this.
The last few times I saw this pin on auction it sold for $90 - $115.
9 months ago it brought $175 - $225.
The panelist pin which was selling for $150 now brings about $75.
Its like most collectibles its worth what someone is willing to pay for it. I wouldn't worry what value it has just enjoy it as a MEMORY of your experience on stage!