I understand that lathe turned handles demand more money and the quality is nicer but what I don't understand is what makes them so much nice? I understand how turning down on a lathe works and that part physically makes sense but what is the added benefit over molded?
I don't know if this is an explanation, but the end results of a turned handle are much better in terms of you can customize the cut and design of each individual handle versus a mold which creates only one pattern. Two see more, here is Oscar11's brush handle making thread. http://theshaveden.com/forums/threads/brush-build-along.26662/
When molding resins, you get seam lines. If done correctly and polished after, they can be barely noticeable, but will still be a weak point that could cause long-term failure. Overall, it's a small increase in quality for a significant price. Such is the way of luxury items.