I was watching all of those, interested to see what they'd go for. That card has been strong at $250+ for nearly a decade. I remember buying out a store on those boxes way back in about 2003 for 10 bucks each. Didn't hit an auto but people paid around $10 for just the base set itself at the time. But, anyway, you're right on scarcity. It's very rare that even one shows up for auction once or twice a year... let alone six at once! It got my attention but I passed on adding one. You got a great card, for sure. Since no company makes well designed/auto'd music cards, that's a gem to hang on to.
BUYING: 2001 UD NFL Legends Autographs - Daunte Culpepper - $300. Steve Young - $350.
BUYING: 2004 Ultimate Collection Jsy/Autos/25 - Culpepper, Carr, Theismann, Brady - Paying $450, in case you like money.