They say it is the custom work and quality parts that go into the pistol that jack the cost up into the stratosphere; this includes higher quality target/combat sights, custom fitting of parts, custom made barrels, custom style grips, etc., etc., and etc.
Custom pistol makers like to advertize their product as being able to do something the others cannot, like group to 2.5" at 25m and be totally reliable with all sorts of ammo. The truth is that you can find that in a out of the box and off the shelf pistol. jmtcw.