I know a bit about this set as I am just a few cards short of finishing it. Each Home Team Advantage store that registered got a "Gold Rush" promotional box to run a party when 2012 Topps came out. Each box had balloons, banners, pins & a pack of 30 gold rush stamped cards. As far as I know the packs were random. All 330 cards in series 1 exist but I think there may be some short prints as I have not seen some of the cards in a long time. I also know Topps did a crappy job sending the kits out to stores as many never got it. My feeling is there may be as low as 20 to 25 of each card.
Here is the correct link to the Baseballcrdpedia site for this set, they have it listed as a promo.
http://baseballcardpedia.com/index.p...2_Topps#Promos