Probably not many. The median rent reported in the census was 108.

Per state breakouts: https://www2.census.gov/programs-surveys/decennial/tables/ti...

Very few, 300 USD was considered rather high in my area back then, maybe a house would be 300. That area is now in the top 5 expensive areas to rent.

In the late 80s early 90s I was paying 350 USD for a 2 bedroom.

My parents bought the home we grew up in, which is located middle of Queens/NYC for ~$30k around 1977/8. It sold most recently for $3M. Rents were typically well under $300mo. $150 in not so great areas. That was a high inflation time though.

Today, I live in a small city in a house I bought for about $200k 20 years ago. IIRC, it sold for $80k around 1992. Worth about $450k today. A decent 2BR apartment rents for like $2k here, a nice one >$2700.