Quandl has neighborhood level housing data and a good API. Is there a way to use their API to get the same data from 2009? If not, is there another source for historical neighborhood level housing data. In particular, average or median price per square foot?
Have a look at Zillow's historical data. For example, this http://files.zillowstatic.com/research/public/Neighborhood/Neighborhood_MedianValuePerSqft_AllHomes.csv is a dataset of neighborhood level median $ / sqft. Also, Zillow has a great api that you can use to programmatically pull and process the data. If you are a python user, check out the package PyZillow for more detail.