Iron Man #55 (February 1973) is a special issue that introduces not one or two, but multiple characters. It sees the first appearances of the powerful villain Thanos, the Guardian of the Galaxy Drax the Destroyer, Starfox of the Eternals, Kronos, Mentor, Blood Brothers, and ISAAC. Since their introduction in Iron Man, Thanos and Drax have played important roles in major Marvel storylines like The Infinity Gauntlet.

When Iron Man #55 arrived on comic shelves in February 1973, the book carried a cover price of 20¢. Later that year in The Overstreet Comic Book Price Guide #3, Robert M. Overstreet priced a Near Mint copy at 25¢. It saw a solid increase in value to $3.75 seven years later in the Guide #10, and was at $8 in 1990’s Guide #20.

Iron Man #55 saw significant growth in the next decade, landing at $75 in the Guide #30. Its momentum continued upward to nearly four times that amount in 2010’s the Guide #40 when it was valued at $285. For the Guide’s milestone 50th edition, the book was up to $1,600. Four years later in the Guide #54, a Near Mint copy of the first appearances of Thanos, Drax, and the others was up to $2,000.