James said he was wowed by the $292 million, 10-year deal the Detroit Tigers gave slugger Miguel Cabrera.
"I wish we didn't have a salary cap," James said Friday night before facing the Detroit Pistons.
James said he would opt out of his contract this summer with the Heat if he could get the same deal.
"The best players in each sport should be rewarded," he said. "It would be nice to sign a 10-year contract for $300 million. I would do it. I would do it for sure."
The NBA salary cap, though, would prevent any team from giving James a similar contract. He is one of the league's highest-paid players with a six-year deal worth roughly $110 million.