I don't have a citation for construction costs, and I will concede that there are many factors that may make some low density developments cheaper per unit then some higher density development.
However, construction is only part of the picture. Low density development imposes terrible financial costs for cities that contain them. That's because the taxable value per square mile is much lower, but infrastructure (sewer, roads, etc) has the same per-mile maintenance and replacement costs. The infrastructure maintenance costs in many low density developments is often greater then the amount of tax revenue the development generates.
For more information on the hidden costs of low density development, I can't recommend this video [1] by Not Just Bikes enough.
No it doesn't, the cost to tear up a street in a high density area is much higher than it is in a low density area, especially if we are looking at hidden economic costs.
> High density housing gets bogged down in reviews and permitting,
Yes, because it's more high stakes and should be subject to a greater level of scrutiny than a 1-2 story single family dwelling. Check out the Millennium tower debacle or that apartment building that collapsed in Florida if you think otherwise.