Well, I just did. This was designed using CATIA (a reminiscence from school). And then I had it made at Sculpteo to test it in high quality resin.

P1000585.jpg

Honestly, not so difficult once you get the hang of it. You can probably setup some templates as well to re-use a maximum of stuff each time.
I don't think this is very interesting to do repeatedly in a 3Dprint service. You can probably bring the unit price down under a $ if you do it repeatedly and set up batches in your own SLA / DLP printer. Otherwise ...