2012 Topps Gold Rush

There were 30 of these cards for sale on the bay the other day, no one bid on them, so I did.  It was three lots of 10 each for $2.50 plus $2.50 s&h.  I won all three lots and got them today.  30 cards no duplicates, ranging in numbers from 20 to 306.  The Gold Rush logo is in the upper right or left corner, always directly beneath the Topps logo.  Sometimes it intrudes on the picture obscuring faces and such.  There were no huge stars in the bunch, Mariano Rivera being the biggest, two cards with the RC logo and two checklist cards which feature season highlights on the front. The one Marlin card I got does feature the new Marlins logo and colors on it, but thankfully Topps did not airbrush the new uniform on the player.

In the bottom right hand corner of every card is the Topps website address followed by a code number.  The code number is the same on all 30 cards.  Does anyone have any idea what I got.