Yeah, the rates soared in the 1970s, and went over 20%. The 1980s also gave birth to Adjustable Rate Mortgages, in an effort to get more borrowers with the promise of lower rates a decade later. Which then of course led to predatory lending practices when they'd start with a low rate, switch to a high rate, and the borrower would default. So in the 90s, with interest rates still high, regulation was passed to lower the capital requirements for Fannie & Freddie to give out loans - leading to more lending than could be covered by capital, leading in 2008 to a spectacular global "whoops!".
I think the housing prices are high because the market can get away with it. If I'm selling a house, new or old, I'm gonna price it at what the market values it at, even if it cost less to produce or if I didn't pay that much for it. And the value of it will keep going up as long as there appear to be buyers for it, and most cities in the country aren't losing value as long as the economy grows.