Over the years, the price of gathering an extensive gaming collection has sky-rocketed as limited-release items become even rarer, and the Super Nintendo had its share of unique cartridges. Most of them were made for special promotions or for use in conjunction with Nintendo Powerfest tours, meaning they've become even rarer as time has gone on.

Desire to collect these cartridges has only increased as the gaming industry itself has grown.  As more and more of these relics of a bygone era are snatched up, lost or destroyed,  already rare cartridges are only going to become harder to find. Here are the five rarest SNES cartridges that will cost (or, if you're lucky, earn) a pretty penny.

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5. Star Fox Super Weekend Cartridge

starfox weekend competition

In the United States from late-April to early-May 1993, Nintendo held a competition to promote Star Fox. It featured a special cartridge that had shortened versions of the game's Asteroid and Corneria stages with added challenges designed specifically as a means to judge winners. Based on completion time, participants that qualified could win prizes such as expensive trip packages.

It's estimated that only about 2,000 cartridges were made for the competition, serving as the basis for its rarity. According to PriceCharting, the current running price for an opened or loose version of the Star Fox competition cartridge runs close to $1400, while a sealed or complete version can fetch upwards of $2100 depending on quality.

4. Exertainment Mountain Bike Rally/Speed Racer Duo Pack

exertainment mountain bike rally speed racer cover

Designed as a tie-in for a stationary bike developed by Life Fitness, one of the first in a long line of wheel-based Nintendo peripherals, this was a double pack that contained both Mountain Bike Rally as well as a Speed Racer title. Life Fitness' stationary bike came installed with a piece that would allow it to link up with a SNES, any momentum earned during exercise transferring over to the protagonists on screen and their 16-bit bicycles.

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This duo pack was never intended to be sold separately from the stationary bike and, as such, became increasingly hard to find over the years. Even during its initial release it wasn't easy to acquire, since the stationary bikes were not affordable or widely available. These days, loose copies of the games can bring in around $1,300, which a complete version of the duo pack is worth about $2,700. The complete version with the stationary bike is worth upwards of $4,000.

3. Donkey Kong Country Competition Cartridge

donkey kong competition version

Originally a part of the Nintendo Powerfest held in 1994 and later used in the Blockbuster World Video Game Championships II, the competition version of Donkey Kong Country is similar to Star Fox's competitive version. Levels were chosen from the fan-favorite entry in one of Nintendo's longest running franchises and tweaked to encourage higher scores. It also added a time limit for the competition and removed bonus levels as a way to streamline the event.

While there were supposedly more copies of the competitive version of Donkey Kong Country, with the estimated original print being around 2,500 units, it has slightly higher price tag when compared to its Star Fox counterpart. A loose version will cost around $2,100, while a complete version can pull in upwards of $3,500.

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2. Nintendo Campus Challenge 1992 Cartridge

Nintendo set out on a tour of North American colleges in 1991 and 1992, the second being a chance to showcase the SNES. Though not as rare as its NES counterpart, the cartridge for the 1992 leg of the tour is scarce, with only two copies known to still exist. It was crafted in a unique shape to accommodate the different games that formed the challenge, adding to the interest of collectors.

With only two even available, often not at the same time, this oversized cartridge serves as a unique relic from a different era in gaming. This historic significance has only grown over time, and as it stands, only loose versions of the cartridge exist, costing around $4,000.

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1. Nintendo Powerfest 1994 Cartridge

In 1994, Nintendo would  tour North America, this time as part of the Nintendo PowerFest '94. Once again, special cartridges were produced with truncated versions of games, a scoring system devised based on the mechanics of each. Winner from various towns went on to form teams for a world finals, eventually crowning Mike Iaross Nintendo World Champion of 1994.

There were only 33 copies of the cartridge made, but 31 of them found their way back to Nintendo and were recycled for parts. However, there are still two in existence today, though there's only selling data available for one. Its listed price is over $17,000, giving the cartridge the distinction of being both the most expensive and hardest SNES game to track down.

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