It’s not your imagination, it is expensive to live on the SF Peninsula, after all we have the richest town in the United States right here – Atherton. According to a Bloomberg article ( Link to Article), Atherton California has the highest average household income for all of the United States ($443,403/year) and Hillsborough is 6th ($350,917/year).
When you consider the high incomes on SF peninsula coupled with limited housing (no more land to build on around here), there is only one possible result, high home prices! The law of supply and demand is very much alive and when there’s that much money around, then things will get expensive. Last year, the average price for a home in Atherton was $8.2M; the average home size was 5,500 SqFt and sat on about an acre of land. The most expensive home sold in Atherton in 2018 went for $23,500,000, it had 10,586 SqFt of living space on almost a full acre of land.