A box of old Nintendo cartridges in Wisconsin looked, at first, like the kind of retro gaming find that might bring in only a few dollars apiece. Then collectors realized the games were not ordinary copies of Super Mario Bros. and Duck Hunt.
Inside were 97 individually wrapped Super Mario Bros./Duck Hunt cartridges accompanied by pristine manuals. Research into their labels, manuals and manufacturing codes indicated they represented a previously undocumented late-production variant.
The cartridges had spent years forgotten in a storage unit connected to OneStopWonders, a retro game store in downtown Waukesha. Owner Kevin Braun had considered selling them for roughly $10 to $15 each before Nintendo collector Jason Ganos examined the box.
Five of the cartridges eventually received perfect PSA 10 grades, and three copies are scheduled to be offered through Goldin Auctions beginning August 12, according to FOX6 Milwaukee.
The Shop Nearly Sold the Games for About $15 Each
Ganos, editor-in-chief of Nintendo Wire, said Braun asked him to help sell some of the merchandise the store had accumulated. Braun then told him about a box of NES games he had purchased years earlier and forgotten in storage.
Super Mario Bros./Duck Hunt was bundled with Nintendo Entertainment System hardware and remains one of the most recognizable NES cartridges. Braun had considered pricing the copies at about $14.99 each. Instead of immediately listing them, Ganos began researching why so many apparently unused copies had survived together.
The Games May Have Escaped a Precious-Metal Recovery Operation
The history of the box came from the person who originally sold it to Braun. According to Ganos, that seller said his grandfather had operated a precious-metal recovery business that processed unwanted circuit boards and other electronics. Nintendo was reportedly among the companies whose material reached the business.
The story was that the cartridges were supposed to be broken down so the gold on their contacts could be recovered. For an unknown reason, this box survived. It reportedly remained in a garage for more than 20 years before eventually being sold to Braun.
Physical markings on the box provided additional clues about its history. Ganos found Japanese labeling, a Nintendo of America reference and an inventory sticker describing the contents as “Mario – Hunt Remanufactured NES.” The box was marked for 100 cartridges, explaining why the discovery of 97 meant three were no longer present. Its shipping label was dated December 19, 1995.
Collectors Found a Version They Had Not Documented Before
The discovery became more significant after Ganos shared photographs with experienced video game collectors and grading specialists. Two grading-company representatives separately contacted him after noticing unusual details.
Ganos then opened one cartridge so its internal board could be examined and compared the cartridges and manuals with known examples. The back labels differed from previously documented versions. Rather than the familiar English-only labeling, the newly found cartridges carried multilingual text.
The manuals contained another distinction. Known copies used the wording “maintenance or repairs,” while the newly discovered manuals used “maintenance or service.” Manufacturing codes on the cartridges and manuals pointed to production in 1993. One code, 9340, corresponds to the 40th week of that year.
Ganos believes the games may have been produced as replacement inventory for refurbished consoles or warranty service, or possibly for a bundle that was planned but never released. No definitive explanation from Nintendo has been reported.
Five Cartridges Received Perfect PSA 10 Grades
Condition became the other major part of the discovery. These were not heavily played cartridges pulled from old consoles. The games had remained individually wrapped, with manuals that also appeared unused.
Ganos personally transported all 97 cartridges to PSA’s California headquarters for authentication and grading. The first group produced scores of 9.6, 9.8 and a perfect 10. By the time grading was completed, five cartridges had received PSA 10 grades. Ganos told FOX6 that, to his knowledge, PSA had never previously awarded a perfect 10 to a Nintendo or NES cartridge.
The Auction Will Show What Collectors Are Actually Willing to Pay
Three cartridges are scheduled to be offered through Goldin Auctions beginning August 12, including one of the PSA 10 examples. Until bidders compete for them, there is no established market price for this newly documented variant.
Some coverage has suggested four-figure values for the high-grade cartridges and potentially five figures for a PSA 10, but those remain estimates. An early sealed copy of Super Mario Bros., for example, sold for $3 million at Heritage Auctions on June 12, 2026. That cartridge was a different production version, sealed in its original packaging and graded PSA 9.6 A++, so its record price is not a reliable estimate of what the Waukesha cartridges will bring.
Do Not Assume a Common Game Is a Common Version
Before selling older cartridges in bulk, owners should examine label revisions, manufacturing codes, manuals, packaging and other identifying details and compare them with documented variants. Cleaning, opening or altering an unusually pristine item before obtaining expert advice can also affect collector value.
Condition should be documented with clear photographs before a valuable item is shipped or handled extensively. For potentially significant finds, opinions from established collectors, auction houses or professional authentication companies can provide more information than a generic online price search.