I've been house-hunting for a while and changed targeting district few times due to my circumstance changes. The mostly used website is Trademe property, as it has sort of up-to-date information. If vendor is not lucky enough, the listing status will change from "To be auctioned" to "Price by negotiation", or even a specific "Asking price". Some in my watch list went that way, and some even changed asking price, lower or higher. I wonder if I can know the market better with full change history, and then a Python spider was created which can sprawl listings from Trademe and save a SQL Server database through Asp.net MVC API. It is too troublesome to check price history by SQL Management Studio, so Chrome extension came into my mind.