With the flame of the Games flame already lit in ancient Olympia, the current cost of the Paris Olympics is approaching €9 billion and is expected to exceed €10 billion. This will require additional financial support from the government, even though the event is organised on the principle that "the Games finance the Games."

"The risk zone is now," a government source told AFP, with 100 days to go before the opening ceremony. The Tokyo Olympics costed €12 billion, according to Japan's national auditor, almost twice as much as estimated in the original bid. Rio 2016 was plagued by corruption, with local organisers estimating total costs at €11.8 billion, more than half of which was spent on infrastructure.

Estimates for London 2012 range from €12 billion to €15 billion. The cost of Beijing 2008 reached €40 billion, according to external experts, while Athens 2004 added to Greece's national debt with a final cost of €13 billion.

In Paris, the expenditure is split between two bodies: the Organising Committee for the Olympic Games (COJO), responsible for managing the competition, and the Olympic Delivery Company (Solideo), responsible for building the facilities. Both have faced challenges, exacerbated by higher than expected inflation rates.

COJO will exceed its target of raising €4.4 billion from private sources compared to the original estimate of €3.2 billion. The initial goal of achieving a balanced budget has been abandoned. COJO will raise €1.24 billion from sponsors, €1.4 billion from ticket sales, and receives €1.2 billion from the International Olympic Committee.

COJO's costs include stadium rental, preparation of the Village, security, temporary stands and opening ceremony performers. By the end of 2022, COJO increased its budget by 10% due to inflation and will have received an additional €111 million in public funding. According to the French Court of Auditors, COJO made the usual Olympic mistake of underestimating its initial budget.

"There is no reason yet to believe that there will be a deficit," said Sports Minister Amelie Oudea-Castera, while the government has provided a €3 billion guarantee to cover any shortfall. Solideo's €4.4 billion budget includes almost €1.8 billion from government sources (€542 million for the €646 million euro Olympic Village, which will later be converted into housing).

By 2023, according to the budget, public funding for the Olympics had reached €2.44 billion, including €1.3 billion from the national government and €260 million from the City of Paris.

Pierre Moscovici raised his estimate of the final public contribution to "between three and five billion euros". Oudea-Castera also argued that even if the final cost reached €10 billion, it would still be relatively cheap compared to other Summer Olympics held in this millennium.

"These budgets are probably the most scrutinised in the history of the Olympics" and "the most restrained (in terms of organisation) in 20 years. There's no reason why it should be five billion euros," he said. 

The final figure will only be known "after the Olympics", Moscovici concluded. The Court of Auditors has been asked to produce a report by autumn 2025.