belt
A good holster needs a good belt, and every day dress belts in my experience, are not stiff enough to offer adequate support to help a holster, even a good one, stay close to the body. Forget about a dress belt bought at Wally World or Rural King for the most part.
There are belts intended for CCW use, with double thickness of leather if you are old school, or synthetic stiffeners or some combo of both. Assuming you have a quality holster to start, a belt to finish the rig should cost about as much, maybe more.