The cost of building Cowboys Stadium has hit its official ceiling at $1.2 billion. Previously, Dallas Cowboys officials described the team’s new palace in Arlington as a $1.15 billion stadium.Some rounded up to $1.2 billion, but we decided against that since the rounding involved about $50 million.That’s real money even for someone as wealthy as team owner Jerry Jones.he cost of Cowboys Stadium has fluctuated – sometimes wildly – in news stories and on Web sites. It was sometimes described as $1.2 billion, which could be attributed to rounding. Recently, some places have also referred to its cost as ranging from $1.25 billion to $2 billion.