123k seems to have been the median for a new home in the country when I googled it, average was higher. A bit of googling says that the average (not median this time) amount for rent in the US in 1990 was 447.

Think they just googled average numbers for 1990.

Average is heavily skewed up by places like NYC existing.

Oh and average new home sizes have gone up, though not as drastically since 1990 since they got pretty big by then already, but compared to the 1950s, it's up 3x.