I notice you have specifically notated the zip code - 75243 - currently there are 5 properties for sale that are at least 5 bedroom, 3 baths, 2 car garage. These range from 360K to 1.5M, 3,386 - 7,935 sq feet, year built 1971-1999. In the last 6 months there have been 6 homes sold that fit the same criteria - 150K-427K, 3,028-3,908 sq ft, 1975-1979.
As you can see there is a large range here. When selling a home there are many factors in pricing including - location, age, amenities and condition. When buying the main question is what are you want and what are you willing to pay. As you can see there is a very large range of homes currently for sale in this zip code.