Each Multiple Listing Service will be able to track the sales over the last few years. A realtor can help you with that data. In the Raleigh North Carolina area, we can go back about ten years. If you want to check prices yourself, try the county tax office in your area. That list of sales will include for-sale-by-owners, too. Remember however that sales which occured two years ago are no longer valid comparisons to what a home is worth today. In many sections of the country home prices have devalued. You also need to consider the law of supply and demand, and check current competition to find a current value for a home.