I have no info in how long and how much this might cost you as I have never even considered this. I do have an "opinion" on what protections it provides you as a creator. It only provides you (imho) protection if you are willing to find and go after violators.
I am overly cautious of copyright material as are most others that I know but I have seen lots of what I would refer to as copyright infringements on the web. I often will purchase a pattern if I want to recreate it (or part of it) just to support the creator and their ideas even though I could easily redraw the quilt in EQ8. Good luck - and I hope, if you choose to do this, you will share the process?