Hey guys!
I'll toss my 2 cents in here as well. (Please bear in mind that I ABSOLUTELY HATE to make gun belts - this sure ain't a sales pitch)
A proper gunbelt is designed in such a way as to lay flat on the hip bones (which are narrower at their top - so the belt needs to be curved) for comfort, and provide the support of a gunbelt, while having the appearance of a dress belt.
Secondly, all leather is not created equal - a really good belt needs to be cut along the animal's spine - this portion of the hide is very supple, yet very tough as well. It is sort of the "fillet mignon" of the hide, so it will be expensive. Also, the majority of the strength of a piece of leather is found in the first 1/10th of an inch of the grain (smooth side) of the material. Subsequent thickness beyond that does add more body, but little additional strength. For this reason, the belt needs to be constructed of two layers of this really expensive "fillet mignon" leather to have sufficient lateral stiffness. It needs to be properly bonded together (or else it will squeak) and stitched from AT LEAST #277 bonded polyester or nylon thread. The finish should be acrylic ( lacquer will tend to check and crack, and oil will soften the belt to the point where it is useless.)
All of this adds up to being a royal pain in the butt to do, so that is why a premium concealment belt will cost in the neighborhood of a hundred bucks. (my materials cost alone on a belt is about twice what you pay for the "wally world" special.)
For IWB holsters, there is a possible alternative - several companies make "instructor's belts" of multiple layers of nylon webbing stitched w/ multiple layers if stitching. I have no real experience with them so I cannot offer a recommendation. However, many of my customers report good results with this approach, so I think that it probably is worth investigating.
All in all, there is more to a gunbelt than meets the eye - and the right belt will allow your holster to function at it's full potential. The wrong belt can be a disaster.