I really do like the design idea behind the Uniloc ? spelling , but they are a very precise piece of engineering. Any chalk dust or other contaminate can make them lock up solid or bind on the locating barrel.
As far as calling it expensive, is just a relative term. What some make themselves is actually more expensive, but just that they do not need to have capitol tied up in having the parts on the shelf.
For myself, I would prefer that they had the spigot on the handle side and the recess on the shaft side.But very few make this arrangement.
Neil