LOS ANGELES — With no shade from the Southern California sun, the 90,000 plastic seats inside Los Angeles Memorial Coliseum have faded almost to white in some places. The handrails have rusted, and the steps have grown treacherous where concrete has been patched countless times.

Built for the 1932 Olympics, and used again as the host stadium in 1984, the Coliseum stands as a symbol of what a third Summer Games in Los Angeles would offer in 2024.

No matter what repairs are undertaken, this Coliseum will never offer the grandeur of recent Olympic stadiums in London or Beijing. But many of the venues are already in place here, which could help make the Games in Los Angeles billions cheaper to put on than they would be almost anywhere else. The office of Mayor Eric Garcetti projected that the cost of hosting the Games would be about $4.5 billion, including a $400 million contingency fund. The Los Angeles Times first reported the mayor’s cost projections on Monday.

The International Olympic Committee president, Thomas Bach, has pushed for a shift toward less expensive Games in response to widespread public resentment in recent years when hosts like Beijing and Sochi, Russia, poured billions of dollars into their Olympics. Los Angeles, in some ways, has emerged as an economically sensible option for 2024.