Hello Dev. The good news is that with your requirement of being within 1.5 hours of DFW airport, you could technically live in Oklahoma. :)
There are always pockets that differ from this logic but typically, the further north you go from DFW, or the closer you get to Ft Worth, the better deal you will find. I currently live in Frisco but it is becoming congested and the existing homes at $400k or above are starting to sit. You at correct in that it would be a challenge to find a home over 3,000 sq ft for $350k or below. One place I would recommend looking is in Celina which is about 15 min north of Frisco and where the sprawl is expanding to. They expect to be close to 100k population by 2024 I believe. Look in the zip code 75009 there is a subdivision called Carter Ranch among one of the areas you can still find the square footage you are looking for. There are a ton of communities here like that in towns like McKinney, Anna, Melissa, etc. Get a realtor that knows the area and you should be good on the primary residence.
As far as the investment property is concerned areas closer to Ft Worth seem to be the better deal these days. Good luck!