Deciding to buy a house is a huge financial and time commitment. Not only could the home you choose come with the largest price tag you will ever see, but it will probably take you decades to finally pay off and call your own. Even if you do decide to sell somewhere down the road, you will more than likely spend more money on this asset than any other you will ever own.
For this reason, you want to make sure that you get the best possible deal. You may also want the opportunity to walk away if it turns out not to be the best option for you. You could give yourself that peace of mind by including contingencies in your residential sales agreement.