When you review the performance of GoCollect's Collectible Price Index, you'll see that the 50 comics that make up the Golden Age CPI have produced highly predictable returns over the the past ten years. Unlike the wild fluctuations of the other CPIs, which display a lot of volatility, the Golden Age CPI is like clockwork -- a nearly perfect straight line producing a steady 79% return:
In the other CPIs, you'll see huge jumps in value during early 2021 due to the pandemic-fueled "comic boom," but the data suggests that Golden Age comics were more or less immune to the effects of the boom (and the subsequent market collapse that followed in 2023 and 2024).
Still, not all 50 books in the Golden Age CPI have contributed equally to the Index's rise in value over the years. Over the past year, the Index is up nearly 5% or 232 points, and the majority of those additional points have come mostly from two Batman issues: Detective Comics #38, and Detective Comics #31.
Detective Comics #38 has contributed an additional 183 points to the Index over the past year.
Collector interest in the first appearance of Robin is the biggest reason why the Golden Age CPI has risen substantially in value over the past year; it has contributed an additional 183 points or 48% increase.
It has a beautiful cover by Bob Kane that prominently features the Boy Wonder's introduction; you couldn't ask for a better cover for a first appearance. This particular CGC 8.0 copy of Detective Comics #38, the third highest grade on the CGC Census, sold for $132,000 just a few months ago in January 2025:
Earlier this month, however, a CGC 6.0 copy sold for $45,600 which is surprisingly lower than another 6.0 that sold for $64,000 back in March 2019.
Detective Comics #31 contributed an additional 49 points to the Index over the past year.
While not quite as hot as Detective Comics #38, Detective Comics #31 has also provided a big lift to the Golden Age CPI. Drawn by Bob Kane himself, many think Detective Comics #31 has the greatest Batman cover of all-time:
This haunting cover depicts a brooding Batman looking over a gothic castle partially obscured by mist at the top of a mountain with a full moon looming behind him. This is really the first image of the "dark knight" that we all know and love today (and stands in contrast to the more campy depictions of Batman from the 1950s and 1960s).
And it's a mega-grail for reasons that go beyond its cover. Still only the fifth appearance of Batman, it also includes the first appearances of the Monk, Julie Madison (Bruce Wayne's first love interest in comics), the Batplane, and the Batarang.
For all of the above reasons, this rarely comes up for sale and when it does, it records huge sales; for instance, the most recent sale of a CGC 4.0 sold for $174,000 on Heritage Auctions back in late November 2024.
This cover is so famous that even its homages are in high demand. Thirty one years later, Neal Adams would draw this replica of Bob Kane's cover in Batman #227:
This replica is quite valuable in its own right with a CGC 9.8 most recently selling for $19,200 in September 2024.
