After selling their small condo nearly two years ago, Ryan and Sandy have been on a frustrating search to buy a house in the Boston suburbs. Having no desire to raise their 16-month-old son in their current rental apartment, they're even more determined to buy a house. They want 3 bedrooms, 2 and a half baths, a large backyard, in a nice neighborhood with a good school district. The challenge? A lot of other families want the same thing in their $400,000 to $430,000 price range. It's a tall order to fill for their realtor, Robert Mailhoit, who is determined to help them find the right home.