In 1970 a $300/month apartment would be ~$2000/month in today dollars. I do think rents are too high as productivity and supply chains are much more efficient. I think in the 70s we were still using black pipe for gas, iron septic lines, and copper pipes for water. But, I don't think new builds or renovations are cheaper inflation adjusted (harder to estimate).
Cost of money (inflation), building, and maintenance is the floor for rents.
Cost of money (inflation), building, and maintenance is the floor for rents.