In just two weeks, Iron Man 3 has earned $700 million at the worldwide box office - and that's with the film only having just opened domestically this weekend. It's safe to say that the first chapter of "Phase Two" of the Marvel Cinematic Universe will repulsor boost past the billion dollar mark and approach Avengers-style record breaking numbers. It already stands as the biggest international opening ever and came in as the second biggest domestic opening (The Avengers having taken the #1 spot last summer).

Iron Man 3's success is fantastic for executives at Disney and Marvel, along with those involved with the film's production, but it also creates a challenge for the studio to bring Robert Downey Jr. back to play the character again come time for The Avengers 2 and beyond. And it's not just Tony Stark they have to worry about.

When signing with Marvel Studios - who've earned a reputation for their strict low-paying contracts - the deals always involve multiple pictures, even more than other typical franchise roles with options for sequels. Chris Evans for example, was sought after for a nine-picture deal, but agreed to doing six. Samuel L. Jackson, who Marvel almost lost during negotiations, ended up signing on for nine films. Mark Ruffalo also has a six-picture contract that began with his appearance in The Avengers.

Marvel Movie Logos for Thor, Captain America, Iron Man 2 and Avengers

Agreeing to long-term commitments is one thing, but the publicized issues talent working for Marvel deal with are the relatively low salaries, something that's been in the media since Iron Man opened in 2008. Jon Favreau met some obstacles in getting a more desirable payday for returning to direct Iron Man 2, the same film which saw the low-balling of Mickey Rourke with a reported $250,000 offer and a similar low offer to Samuel L. Jackson to play S.H.I.E.L.D. Director Nick Fury for the long haul.

In theory, it's smart business. Marvel has a proven track record in finding lower cost, lesser known - even unexpected - actors (and directors) and turning them into superstars, but not before locking them in for a long-term franchise since they're always planning ahead. Robert Downey Jr. however, got around this with his agents renegotiating a sweet deal for him after Iron Man that saw him take a hefty chunk of the gross from The Avengers. His earnings from his appearance was reportedly upwards of $50 million but Deadline reports that it was actually closer to $70-80 with him getting 5-7% of first-dollar gross for his appearances after Iron Man 2, resulting in earnings several dozen times that of his co-stars.

RDJ wasn't joking at Comic-Con last summer when he said his agents were overjoyed with their position. Downey Jr., much like his IM3 co-stars Gwyneth Paltrow and Don Cheadle, isn't signed for any additional films, but the Tony Stark character is already written into the script of The Avengers 2 (Joss Whedon handed in his first draft recently) and Marvel Studios President and film producer Kevin Feige went on record saying Stark is "100%" part of the future of the franchise.

The Avengers Box Office

If Robert Downey Jr. banked $70 million plus with The Avengers and already has earned over $35 million just from what Iron Man 3 has done in two weeks, how much will Marvel Studios have to pay him for return appearances in The Avengers 2 and The Avengers 3, and is Iron Man 4 still a possibility? More to the point - what does this mean for his Avengers co-stars who earned much, much less than him in the first team-up (reportedly $2-3 million for Evans, Hemsworth, etc.)?

Thing is, not everyone is signed for The Avengers 2 (see: Chris Hemsworth) and with its record-breaking expectations, it's going to cost Marvel and Disney a lot to keep everyone aboard. Deadline reports from their multiple sources that at least some of the reps and stars of the film aren't happy with their deals and Marvel's tactics. Marvel is allegedly firing back with threats of lawsuits and recasting. Terrence Howard was the highest paid actor in Iron Man and he was replaced for the sequel, despite the financial success of the first film and the confidence in the franchise.

In an interesting twist, the man who was paid the most and the one in the best bargaining position going forward is also the one person who might be essential in bringing everyone together. Deadline's reps claim that the stars of The Avengers are rallying behind Robert Downey Jr. and that he is their de facto leader of sorts.

"He’s the only guy with real power in this situation. and balls of steel, too. He's already sent a message that he’s not going to work for a place where they treat his colleagues like shit."

Will he hold out on signing unless the other Avengers get better deals as well?

For comparison's sake, RDJ movies vs. non-RDJ movies at the box office:

With.

  • $585 million - Iron Man
  • $624 million - Iron Man 2
  • $1,512 million - The Avengers
  • $711 million - Iron Man 3 (in less than two weeks)

Without.

  • $263 million - The Incredible Hulk
  • $369 million - Captain America: The First Avengers
  • $449 million - Thor

Robert Downey Jr. is Marvel's most bankable actor, and Iron Man 3, boosted by the The Avengers success last summer, is on track to destroy the box office numbers of any previous Marvel Studios solo character feature film. We won't be able to compare properly until Alan Taylor's Thor: The Dark World releases this November, testing the fall release schedule for Marvel, but it's a safe bet that it won't top IM3, which may prove to be the year's biggest box office hit.

Iron Man 3 arrives at his lab

According to THR, Robert Downey Jr.'s people are already in negotiations with Marvel Studios to return for the Avengers sequels, but there's no talk of Iron Man 4 yet. The actor has not been shy about expressing interest in working on other types of films and having more time away from the Stark role, even hinting at retirement.

Knowing the enormously high salary expectations for Robert Downey Jr., is he worth price to Marvel? According to Cowen and Co. industry analyst Doug Creutz, he is, claiming that losing him would drop the earnings on films with Tony Stark appearances by 9%. There's no telling how arbritary number is calculated, but logic would dictate that a Robert Downey Jr. Iron Man appearance would be worth more than a non-Robert Downey Jr. Iron Man appearance.

The other, albeit far less realistic possibility, is that Marvel could actually recast. They did so with Mark Ruffalo taking over the Bruce Banner role from Edward Norton and as mentioned above, Cheadle taking over the Rhodey role from Terrence Howard - both to great success - but Downey is a different beast all together and is arguably the face of the Marvel Cinematic Universe.

Iron Man 3 Second Trailer Discussion

The movies and characters are not going away, but eventually, the actors will. Batman and James Bond lived on through multiple recastings - their latest being their most successful - and so to will Tony Stark and Iron Man. Even if for some crazy, unexpected and disappointing reason, Robert Downey Jr. were to say farewell to Earth's Mightiest, The Avengers 2 would earn a billion dollars with someone else in the role, but that wouldn't be good for fans, the series, or the studio.

It's a shame that a franchise built around superheroes saving the planet is slightly clouded by the reality check of it really being about big business and the debate over who gets what from the billion dollar pie. But the good news is, the future is bright for the Marvel Cinematic Universe, and bigger movies and new characters are on the way.

Iron Man 3 releases May 3, 2013, Thor: The Dark World on November 8, 2013, Captain America: The Winter Soldier on April 4, 2014, Guardians of the Galaxy on August 1, 2014The Avengers 2 on May 1, 2015, Ant-Man on November 6, 2015, and Doctor Strange sometime after that.

Let me know on Twitter @rob_keyes if Marvel should pay whatever Downey wants to come back in Avengers 2 & 3!

Sources: Deadline, THR