Where is the line between just enough and too much? Comic publishers seem to have a hard time finding it.

When it comes to comics, publishers rely heavily on each generation’s cash cow. Whether it’s Marvel or DC, it doesn’t matter; they both pull the same trick, and fans notice.

Back in the 1960s, it was the Human Torch, then Spider-Man, and throughout the 1990s, Marvel fans saw Wolverine grace the cover of virtually every title they printed. These days, it’s Deadpool, but I’m noticing a shift towards Venom (just look at the volume of “Venomized” cover variants the next time you are at your local comic convention).

What inevitably happens is fans demand more of their favorite characters, and the publishers deliver because it’s profitable. But then they don’t know when to stop, and it all becomes too much. That’s when those oh-so-valuable first appearances start to take a nosedive in price.

As we head into 2018, here’s a couple of first appearances that are losing the interest of their fan base.

THE BATMAN ADVENTURES #12

This is one of the more surprising entries on this list. Granted, it’s still valuable, and it brings a high price. After all, this is the first appearance of Harley Quinn in comics, and it is always a popular issue for collectors. However, it’s been losing value on most grades throughout the year.

Like I said, Harley’s first appearance still commands a hefty price tag. According to GPA for Comics, a CGC 9.8 still brings close to $1,600. The problem is that it was averaging almost $1,900 just last year. How about a 9.6? It’s lost nearly $100 in value in a year while a 9.4 has surpassed that $100 drop. In fact, all but two grades of The Batman Adventures #12 have seen a decline in value this year.

What’s to blame for this? The awful Suicide Squad movie certainly didn’t help, although Margot Robbie did a decent job of portraying the Betty Boop-voiced femme fatale. However, the real problem I see is the same that’s happened with Deadpool: oversaturation. Between movies, cartoons (DC/Warner Brothers announced a Harley cartoon series for next year), video games, merchandise, and seeing her name and face in almost every DC title, fans seem to be getting their fill of Harley.

UNCANNY X-MEN #266

If there’s one great thing that could come out of the Disney/Fox buyout, it’s that the Gambit solo movie (the one starring the world’s most famous frat boy himself, Channing Tatum) might be history. God willing, that could be the case, and if it is, then Uncanny X-Men #266 may start picking up. But until then, it is a buyer’s market for Gambit’s first full appearance, and it likely will stay that way in 2018.

Back in 2015, a CGC 9.8 was bringing an average of $365. It’s progressively fallen to $325 in 2017. This is the case for all the near-mint grades of Uncanny #266. It doesn’t start retaining its previous values until you get to a 7.0 and below, and even then it’s sparse.

Gambit has a fairly passionate fan base, and the cajun superhero will remain popular, which is good for collectors looking to sell their copies of Uncanny #266. As previously stated, it is currently a buyer’s market for this issue, and you’re unlikely to get much of a return on your investment. However, give Marvel/Disney time, and he will inevitably be included in the MCU. When that happens, you’ll see prices jump.