"Iron Man 4" is one of those titles that Marvel Studios and actor Robert Downey Jr. continue to allude to, stirring fans' excitement by mentioning that it may or may not happen but with no official decision made.

According to a new report from the Master Herald, it may be possible that the film will happen but only after phase 3 of the Marvel Cinematic Universe. The report says that one of the main reasons why the fate of "Iron Man 4" is not yet confirmed is due to financial concerns. Downey was paid $50 million and then some for the first "Avengers" film and he was paid the same amount for starring in "Iron Man 3." 

With the success of the "Iron Man" franchise heavily banking on the actor's prestige, it is likely that he is demanding for a higher pay this time around. According to a report from the Venture Capital Post, Downey may have already raised his fee to star in "Captain America: Civil War" and the "Avengers: Infinity War" films. 

Variety reported last year that the actor was named by Forbes as the highest paid actor, totalling up to $75 million. He was also listed as the top paid actor in 2013, also accumulating $75 million at the time. 

If the films still prove to be a financial success and if Marvel Studios and Disney still feel comfortable with spending a lot of money for RDJ's talent fee, then he might return for a fourth solo film. If he doesn't, then the studios may still push forward with the project by simply banking on brand recognition. 

As previously reported here, there are speculations that 13-year-old Ty Simpkins may take over as the titular character if the 50-year-old star no longer steps in for the role. The child actor had a large role in "Iron Man 3" and will be old enough to don the iron suit by the time Marvel Studios is done releasing "Avengers: Infinity War" part 2 in May 2019.