How I intend on collecting data

With my data analysis toolbox pretty much wrapped up, I can now start collecting the data. The question is: How am I going to collect the data? First of all, I will contact a few real estate agencies and ask for a number of house prices in the New Orleans area. I am not sure how many houses I will use per sample, though. I will also use web resources to find prices of houses and the average prices of Louisiana and the United States. I will determine whether or not I will find prices of identical homes, probably by square footage and/or amount of floors. Anyone have any ideas or suggestions?