2018 MARKET UPDATE:
This book hasn't really moved for years. It's hot enough to justify its place on this list, for now, but even the fuss around Frank Castle hasn't moved the needle.
2017 MARKET UPDATE:
Punisher is hot property. This book is perhaps less scarce than people expect in high grade, but still, it's his origin story. See also his first full appearance in Amazing Spider-Man #129, which is much higher on the Hot 100.
Prices have softened a bit recently, but it's deservedly higher than this time last year.
Despite a lousy first movie years ago, The Punisher is once again hot property in the Marvel Universe.
Choose your favorite from these rumors:
Although his first appearance in Amazing Spider-Man #129 is more important, more valuable (and more common) and appears higher up on the 100 Hot Comics list, you'll need to track down a copy of this relatively scarce Curtis magazine to read the Punisher's origin back story.
A potential sleeper, CGC 9.8 copies have not changed hands in recent years. You're probably looking at $1,000 or more to acquire one with white pages.