The event is the first promoted directly by F1 owner Liberty, and the company has borne the cost of buying the land for the pit and paddock area and creating the permanent buildings that are on it.
The costs have risen over the construction period, while other expenses connected to putting on the race have also escalated.
An insight into the rising CapEx costs was given by Liberty Media CFO Brian Wilding in a call with Wall Street analysts.
In August, he noted that the company expected to spend "close to" $400 million on the project and that $155 million had been spent in the first six months of 2023.
In Friday's call, he noted that "through the third quarter we incurred approximately $280 million of CapEx related to the pit building structure and track preparation".
That would put the running total for 2023 to the end of September at $435 million, or already some $35 million above his earlier estimate, without counting any expenditure from October onwards.
However, Maffei insisted that some of the costs are one-time only and that the event will be more profitable in future years.
"We did incur significant expense in launching year one in Vegas," he said.
"And that included extra provisions for safety, security and traffic planning, which was required by local regulators.
"And we had several non-recurring items, for example, our first-year-only opening ceremony, and the design and launch of our multi-purpose app, and creation of a fan database.
"We remain highly confident in the increased efficiency to operate there and our growing profitability in years two and beyond. And we remain bullish on the broader value creation at LVGP that far outweighs the increased investment and startup costs."
Source: Autosport