Demographics are a tough topic, because the current population may not be in a position to afford a $370k house in the Fate area, but there are many people who would buy who don't currently live there. While averages are interesting statistics, they do not reflect the robustness or breadth of the accessible market.
Anyone who considers Fate within commuting distance of his job is a potential customer (not just the current residents of Fate). Nearby Heath, for example, really doesn't have any houses as low as $370k. They start around that. An enclave of expensive homes ($350K+) could be successful in Fate, since they already have some. Just remember that the same home in north Dallas would bring in a million+, so if they're not shopping at Preston Center, they may buy in Fate.