FANTASTIC FOUR #51

Cover shows notable spine wear with a chip/tear at the top left edge of the spine and general spine roll causing minor color break along the fold. There is scattered surface wear and small stains/foxing across the cover, along with faint soiling. Corners appear moderately blunted rather than sharp, and there's a small pen or ink mark near the top left near the indicia box. The book is in a protective sleeve which causes some glare; interior and back cover were not assessed.

Fantastic Four #51 (June 1966) presents "This Man… This Monster!," a done-in-one tale written by Stan Lee, penciled by Jack Kirby, and inked by Joe Sinnott. The story follows a jealous scientist who steals Reed Richards' powers and identity to infiltrate the Baxter Building, only to undergo a crisis of conscience that leads to self-sacrifice. Unlike many surrounding issues in the run, the book carries no first appearance, but it is widely cited by Lee and Kirby themselves, and by subsequent critics and the Overstreet Price Guide, as one of the strongest single stories of their Fantastic Four collaboration; it won the 1966 Alley Award for Best Single Story of the year, a rare contemporary industry honor for the title.

Market data shows a broad, actively traded census exceeding 1,000 Universal copies, with steady grade-to-grade appreciation through the mid grades and a pronounced value spike above 9.0, where supply thins sharply (only 24 copies at 9.4 and 8 at 9.6, with none certified higher). Recent sales activity in the 9.0 and 8.0–8.5 brackets shows consistent 90-day and 30-day pricing, indicating a liquid mid-grade market, while the jump to $4,300 at 9.4 reflects the premium collectors place on high-end Kirby art in a story-driven, non-key issue. Demand is driven primarily by Lee/Kirby completists and Fantastic Four run collectors rather than speculative key-issue buyers.

The book trades as a strong mid-tier Silver Age Marvel: affordable and plentiful in lower and mid grades, where most transactions occur, but commanding outsized premiums at the top of the census due to genuine scarcity above 9.4. Buyers are typically Fantastic Four series collectors, Kirby art enthusiasts, and Silver Age generalists building out acclaimed non-key issues; a pristine, unslabbed 9.8-quality copy would be a census-topping rarity likely to draw significant attention at auction given the absence of any such certified example to date.