Many of the same market forces that are inflating prices in nearby Los Angeles are at work in Orange County. There's little land left that can be used for large developments and local zoning regulations are adding to builders' expenses.

"Everywhere you look, housing inventory is scarce," said Appleton-Young.

Many first time buyers have also had trouble getting mortgages. Statewide, she said, neophyte buyers accounted for only about 28% of house hunters recently, down from a historic average of about 38%. That has tilted the mix of home sales toward the high end, she said.