An article in the NY Post addressed the real estate. In coastal Ca., the cost of these homes on the water are anywhere from $4 million to $25 million. Renata's and Madeleine's homes are apparently located in Malibu.
From the NY Post:
“What I learned once I spent a lot of time scouting is that that portion of the central coast of California is very rocky, with those waves crashing up on the rocks, as you see throughout our show. There are beaches, of course, but I can count on one hand how many homes are actually on the sand.”
For that reason (as well as factors such as budget and actor schedules), the majority of the series used LA locations and sets to double as a rarefied Monterey. Both Renata (Laura Dern) and Madeleine’s (Reese Witherspoon) houses are actually in Malibu. Jane’s (Shailene Woodley) modest Craftsman bungalow is in Pasadena. Only Celeste’s (Nicole Kidman) mansion, with its large balcony nestled among the trees, is geographically true (it’s located in Carmel, Calif., Monterey’s more affluent neighbor)."