There is a reason Madison Square Garden Chief Financial Officer David Brynes spent a large portion of the company’s quarterly conference call last month explaining the advertising, marketing and promotional potential for the off-Strip $2.17 billion MSG Sphere project.

The investment community wants to know how the publicly traded company plans to recoup its expenses to build the entertainment attraction behind The Venetian.

The cost has grown by more than $300 million in the four years since the groundbreaking. The Sphere, which is expected to open in 2023, now has a price tag larger than the $1.9 billion Allegiant Stadium, even though the venue’s capacity is one-third the size of the 65,000-seat home of the Las Vegas Raiders.