Most modern special effects include meticulously simulated physics interactions. Have you ever watched Transformers? Watch some of the cuts that show what's actually real. The kind of hardware required to render hours of that material costs tens of thousands of dollars, not to mention the money to hire people who have poured additional tens of thousands of dollars into college educations that instruct them how to use that hardware.
All in all, it adds up to millions of dollars.
However, if you're one of those people who happens to have one of those very intensive educations, you can make that kind of bullshit in your spare time.
