I picked this card up off ebay recently for just over $3 shipped.
It says "Authentic Opening Fay Game-Used Base" on the front of the card. Now does that mean it's from a base used on Opening Day and if so, was it used in the Rockies vs. Diamondbacks game on April 3rd, 2006? Or does it mean that it's a game-used base card from 2006 Opening Day set?
I choose to believe that the piece of base is actually from one of the bases used in the Rockies vs. D-Backs game on Opening Day on April 3, 2006.