I have seem some related questions but none of them seem to have the answer I am looking for. I want to be able to find a website (say like the Multiple Listing Service listings) that would allow me to scrape data from their site about property sales records. In particular, for a given zip code I would like to be able to aggregate purchase histories such as number of houses sold in a particular month and year, and prices (during that month and year) in which the houses sold. Does a website with this type of data to be collected exist?
You are looking for the property appraiser's office for each county to assemble the data for free. Anything above this level is going to be a cost item.
Daniel Miller's answer recommending property appraiser's offices is great, and if your need is confined to a couple of counties, it's not too much work to locate each dataset. However, if you need this information on a nationwide basis, hunting down every single appraiser's data is incredibly tedious.