Some people have been finding an unnumbered Mira Furlan card, photo on the front and bio on the back, in Babylon 5 Special Edition trading card packs.
Here is the story, as excepted from a post by Stephen C. Smith (email@example.com), the author of the cards, that he made to the rec.arts.sf.tv.babylon5.moderated Usenet newsgroup on July 8, 1997:
Mira agreed to sign 1,000 autographed cards in exchange for Fleer printing up a certain number of cards for her personal use. Mira's personal cards were printed at the same time as the rest of the cards. ... Fleer schedules one day at the printing press to print a particular card set. To save money, Mira's were printed along with the Special Edition set.And here is him restating again. (As he notes, there have been various rumors and accusations about the origin of this cards. I believe him - but not everyone does.)
Somehow, by accident, some of Mira's cards got mixed into the Special Edition sets. Fleer doesn't know how many for sure. It does not affect the autographed cards in any way. Mira signed 1,000 cards. ... All of those 1,000 cards are now in circulation (with the exception of a very few they keep on hand to replace damaged cards).
[It is] a card that's even more rare than the autographed card. Eventually, that'll change, as Mira will hand out her cards and they will become more common. For now, there are a lot more autographed cards in circulation than there are the "mystery" card, as people call them.
Fleer is offering to replace the "mystery" card with any other common card from the 72-card set. That's actually quite generous, since the card was *in addition* to what was being printed. It didn't replace anything. Frankly, if I had one, I'd keep it because it's pretty damn rare. But if anyone wants to trade it in, send e-mail to firstname.lastname@example.org and they'll give you instructions.
As to how many were made, I hear that people are estimating that approximately 2000 of these Mira Furlan cards were printed, of which 200-300 made their way into packs (and the rest went to Mira).
So, if you find one - keep it or trade it, and consider yourself lucky.
As to its value, I've seen it selling for $75. And seen it sell for $121 in an auction (8/18/97). And I've seen it listed for sale for as much as $295.
8/8/97: I am told by Moyra Bligh that Mira is now selling them at her convention appearances for $50 each. (It was $35, but she has raised it.) And has autographed them on the back at the bottom, and will personalize them too if you ask.