Halle Berry Co-Star -- I'm Just a Kid, But I'm Earning $$$$ Like a Boss

Halle Berry would love for Gabriel Aubry to take a lesson from her 9-year-old co-star -- because the kid is killing it when it comes to making big money ... on his own.

Pierce Gagnon plays Halle's android son on the sci-fi show "Extant" -- and his paycheck is out of this world ... a cool $25K for every episode of season 1.

According to his contract -- which was filed with the court because he's a minor -- Pierce made $325K for the first season and will collect even more for season 2 -- $26,250 per episode.

Plus, he's locked into the contract for the next 6 years -- if the show lasts that long -- which means he could be a millionaire by the time he starts shaving.

Watch and learn, Gabriel ... is what Halle would say.