In rural markets or areas with limited data, you should attempt to start by pruning down your variables to significant variables at first, adding to the list after you have balanced those. You have several options to help your success, you can include multiple years of data, or in the case of rural markets, solving with adjust only for items like Lot Size. These practices can exponentially increase the credibility of the results.
See the Knowledgebase article Proper Collection of Data for more detail.
See the YouTube video Getting Results in Rural or Custom Markets for practical examples of working with limited data.