HogansAlley

There's been a few European samples of Mario & Yoshi that have sat around for $350 on various sites just last year and there was an SNES Kirby NOE sample that sold around the same price. Granted they're obviously not as popular or influential as Super Mario Bros, but even though they're first party, the majority of prototype collectors only care and spend big if it has differences. If you take a look at the Super Mario Bros. 3 prototype for example (byte for byte identical as retail) that sold on Heritage Auctions in 2020 for a total of $31,200. It was probably bought by someone who had no clue what the market for this stuff looks like, because it was resold one year later at an almost 50% loss. Still way higher than what it's worth, but it's much higher valued than the sample here for a simple reason: It's a true prototype that was from when the game was going through it's localization, not just some sample cart that was sent to a magazine or something similar. This cartridge, like all the other similar ones, are not a 1 of 1. It will just be a matter of time before another one is discovered and it destroys any "extra" value it supposedly has.

The cartridge seems legit to me. Labels on both the front and the EPROMs are exactly as they should be. Is it worth a whole lot? Absolutely not. These are just the usual European sample cartridges that you see being sold for pennies in comparison to "proper" prototypes. These cartridges have no differences and match 1:1 with the retail release. If you still think it's worth that kind of money, simply search sold listings online. First party European samples reach $500 tops. You'd essentially be paying for a shell and paper label here, the PCB itself is pretty low valued considering it's a retail NROM PCB with EPROMs. Anyone familiar with the FamicomBox should also no doubt be aware that early revisions of the cartridges contained these very EPROMs with the same labels (they came in green, pink, and blue), datecode, and all. They were simply recycled. Notice in the photo of the sample the "SSS" product code was crossed out. Attached below is a photo of an EPROM from the Super Mario Bros FamicomBox PCB for reference. Before you say it, no, this doesn't necessarily mean it's a fake. This was common practice for Nintendo to do on these types of cartridges for both NES, SNES, and even Game Boy. In short, don't believe something is worth 10 billion dollars because some random guy on the internet told you Happy collecting.