Actually pretty rare to find as a panel as most were issued as singles in penny packs. The panels were issued in their own separate wrapper (also much tougher than the penny counterpart). I would guess a value of at least $200-300 or more to a Topps specialist (nice condition as well), very nice find Dan!
Here is Dave Hornish's blog with the wrapper these panels were found in being pictured about half way down the page.
http://toppsarchives.blogspot.com/se...Magic%20Photos
-Rhett