The looming bidding war for the NBA expansion team expected to be granted to Las Vegas is shaping up to be the most competitive and expensive sports deal in U.S. history.

The list of potential suitors spans LeBron James and his backers to the company that owns the Red Bull brand, according to people familiar with the situation. The total price tag including building a new arena has the potential to hit $7 billion, according to two sports advisers who have previously sold NBA teams.

Expansion in North America’s biggest sports leagues is rare. The NBA last added a team in 2004 when it awarded a franchise to Charlotte. The NFL hasn’t grown since 2002 and Major League Baseball’s most recent additions came in the late 1990s. There’s also been a boom in team valuations. And Las Vegas has become a sporting destination — hosting the most recent Super Bowl and is adding a MLB team to its NFL, NHL and WNBA franchises.