The writer-artist praised director Joss Whedon and his crew for their work on the film, but said that he resented having to pay for a ticket, and called Marvel Studios' policy on creators' rights into question.
He told Hero Complex: "It's nice to see my work recognised as being worth something beyond the printed page, and it was very cool seeing Thanos up on the big screen. Joss Whedon and his crew did an excellent job on The Avengers movie and I look forward to the sequel, for obvious reasons.
"But this is the second film that had something I created for Marvel in it - the Infinity Gauntlet in Thor being the other - and both films I had to pay for my own ticket to see them. Financial compensation to the creators of these characters doesn't appear to be part of the equation."
Thanos made a brief appearance in a post-credits sequence in The Avengers, hinting at a bigger role for the villain in future Marvel films. Starlin hopes that the cameo will help his own film projects gain recognition.
"Hopefully Thanos's walk-on in The Avengers will give a boost to a number of my own properties that are in various stages of development for film: Dreadstar, Breed and the novel Thinning the Predators," he added.
The Avengers has made more than $1 billion (£623 million) worldwide according to the latest box office figures.
Watch a clip from The Avengers below: