Separate living quarters and guest quarters are rare. Unfortunately, builders and communities have not recognized the booming market for families with your needs. Deed restrictions for single family communities prevent construction of the type of home that you are looking for and most of Frisco falls under these regulations. I ran a search for homes in Frisco and some of the surrounding communities and did not find any homes with separate quarters or a guest house in the price range that you listed. There are many homes with a second bedroom and bath suite downstairs, but these may not provide the privacy that you desire. I did find some homes on larger lots outside of Frisco that might, depending on deed restrictions, allow you to add a guest house without starting with a builder from scratch. If you are willing to look beyond Friso, we have more opportunities to find rural propery with fewer or no restrictions.