I'd like to see that stat--10% off? As in 10% decline--no way. Maybe in a few isolated neighborhoods, but no way market wide. Ask him for his source.
She was talking about the $650k+ market. Her source would be experience in the field of selling 10+ homes a month. She said you might not see the 10% difference in price yet because of seller concessions which do not show up on the final price.
Example would be lets say two similar homes are for sale. One closed in June for $700k. Now people across the street list their home for $700k in November. They end up selling the home for $675k. Only a 4% decrease for arguments sake. Not much difference on the surface when you compare them for MLS stats. But other factors may be involved such as seller pays a portion of closing costs and gives the buyer an allowance of $10k for upgrades. This was unheard of in the summer but is now becoming common place in the market in this price range.
Allowances and seller paid points do not reflect in the MLS data which can skew the numbers.