Yup, all of this seems to be good advice. Look to the north and south of Krum as there are a few cities that have not hit the developer radar yet. You might also look into Van Alstyne, which is a pretty little city, but it would be a hard slog into Carrolton each day since you would have to transverse north Dallas both coming and going. Of course, if you don't mind the tolls there is the George Bush, but you would still have to deal with traffic in McKinney.

But before you buy..... Beware!!!!!!!!!

Some Texas counties have gone to what is called 'unified code' or something like that. An example would be Williamson County which is just north of Travis County. The bottom line is: All the building codes and property codes of the county seat apply to the entire county. IF you are planning on just tossing up a metal building and going nuts in there the city can come out and shut down your shop even if there are no zoning laws where you live.

The things is: It's complicated, but it can be checked out in advance.

Have you looked into buying an old commercial building in downtown Carrolton or Farmers Branch? It might violate zoning laws for you live there, but I have found that claiming your apartment as an office will usually allow you to jump through a zoning loophole.