The remark came during Thursday night's GOP presidential debate.
"If he hadn't inherited $200 million, do you know where Donald Trump would be?" Rubio said. "Selling watches in Manhattan."
Rubio later called Trump "a con artist."
Rubio's website lists a beat-up wrist watch called a "Trump Watch" next to the remarks with the caveat: "You won't actually get a broken Trump watch, but your $10 donation will help Marco stop him."
The watches appeared on the Rubio camp's website at the start of the debate, suggesting Rubio's remarks were prepared.