In Boston, inventories of homes for sale are down 34 percent from a year ago, according to the local Realtors association. In Denverit is much the same. Even in Houston, where housing barely faltered, listings are down 21 percent from a year ago.
Several factors are keeping inventories low.
First, negative home equity. Millions of homeowners are still stuck in place, unable to sell because they owe more on their mortgages than their homes are worth. While more than 3 million homeowners came up from underwater in the past year, 12.2 million are still drowning in mortgage debt, according to a recent report from Zillow.
Confidence, or lack thereof, is also still keeping some sellers sidelined.
"There always is a tendency to time the market, which we know is becoming a little bit harder to do," said Budge Huskey, CEO of Coldwell Banker in an interview on CNBC. "It's an assessment of their overall impressions of the economy. I think there's still a little hesitation. People want to see stronger economic growth, people want to see more progress made toward unemployment rates and just feel better about moving on."
Lack of inventory means it is a seller's market, despite so much hesitance by potential sellers themselves. That will keep home prices strong, unless and until more people decide to list their homes and home builders ramp up production, which they have been so far slow to do.
(Read more: $1 million summer homes)
It begs the question, what is housing worth today, market-to-market? A million dollars may buy a McMansion in Oklahoma, but barely buy a bedroom in Manhattan.
In an effort to gauge differing values, CNBC is trawling the million-dollar market again, this time in a "back-to-school" edition.
Starting on "Squawk Box" this Friday, two reporters will show two homes without disclosing their locations; they will document the interiors, exteriors, marketed features and one unique bonus offered by each home.
Real estate maven Dolly Lenz will decide which house gives buyers a better bang for the buck.
We will then reveal where the two houses are located, and with that added to the mix, Lenz will choose a winner. That house will then go up against the next mystery location on the next show.
(Follow along on Twitter with the hashtag #MillionDollarHome and see the early winners here as well).
—By CNBC's Diana Olick. Follow her on Twitter @Diana_Olick.