The problem is cost. I could print the master wax with a 3D printer that I have, but that part alone usually costs around $75, not including any design time or other costs. The casting in titanium usually costs somewhere in the range of $150 for a short run type of thing. Unless they are casting their wax from a silicone mold and doing multiples, cost will be up there. As I've said, I've seen some from China, who excells at that type of thing, but they weren't very well done skulls. Somewhat embarrassing looking ones that you wouldn't really want around your neck.
Here's the type of detail possible with the printer. This is cast in silver so it can be blackened in the background relief. I have seen some nice ones in silver. Some of those people should be able to have them cast in stainless, which is not as bad as casting titanium.