I agree the costs are high. That is largely a result of the high cost of living. There's additional economically literate funding methods which account for that.

For instance, when infrastructure is built, it causes surrounding land values and rents to rise. It is possible to use that rising value to pay for the infrastructure, via a special assessment.

There is also an issue where the people with the worst infrastructure would be paying the most under congestion pricing, which means that it would be important to prioritize improvements to the most congested areas.