Trading cards based on video games have traditionally not been a wise investment. Often times, they're produced in the millions and have no value other than to promote the game. Nobody bought a pack of Topps Nintendo cards back in the 80s and thought that one day it would fund their child's college education. So thanks to general disinterest, the secondary market for these cards have – save for rare production "proof" cards – almost little to no action.
The one exception? Metal Gear Solid trading cards.
Produced by Konami in 1997 alongside the Playstation title, this was not your ordinary flimsy cardboard. Using acetate technology, the cards were clear and had a glass-like effect so you could see right through them. Each card was also serial numbered. The cards felt like a premium product and were meant to be sold that way as well. Unfortunately, due to weight of the cards themselves, shipping them at the time would have been a costly endeavor. The product was scrapped and the cards were either destroyed or sold to private buyers.
Occasionally you'll see these singles pop up on eBay for exorbitant prices. While these cards don't sell for very much because they are the common base cards, sometimes a card that looks similar to the commons will sell in the hundreds alone. That's because in true Hideo Kojima fashion, there are multiple and confusing parallels (cards that are "special" and rarer versions of the regular cards) in the set. Parallels ranged from something as subtle as a gold foil MGS logo to cards having holes punched in them. Others were die-cut, while some are printed on different colored acetate, and others had a combination of all four.
The biggest "hits" of the set were the super rare insert cards that weren't even guaranteed to show up in a box or a case. A PAL key card insert limited to 4500 recently sold for $200 online. Information on the remaining insert cards are particularly sketchy because of their extreme scarcity. The first are ten one-of-a-kind original art cards by MGS artist Yoji Shinkawa (six appear to have been pulled). Next are regular cards signed by Kojima and/or Shinkawa (actual number of signed cards is unknown). The last of these inserts is probably the most mysterious because they're called "Big Boss" cards and have the words "Only One In The World" printed on them (nine are believed to exist).
Juan Martinez is the National Classic Games Examiner for Examiner.com. Yes, the site that somehow manages to always appear on the top of Google news searches. Sorry.