Sounds like it is very much worth fragging out. Prectice fraggind a bit on the edges and once you get comfortable, give it a try on the "special" polyp. Just dont hurt the polyp you really want to keep.
If you have a colony, might be worth sacrificing a few of the polyps around the single polyp to acheive a good frag of the special polyp of the group. In other words- Frag off a section of the polyps around the special one, then after you get that chunck of, cut the others off till you have the single polyp left.
It will be alot eisier than trying to frag a single polyp out. Just do some research on the how to frag, and all precautions necessary, follow them, practice, then you will be all set! Give it a try!
Sounds like a cool polyp. Frag it and grow it.
Just make sure to find it a nice home in your tank of similar conditions as to what it has now, and give it alot of time. Different conditions could cause it to morph for the worse and not be as nice as it is now. After it grows out, you can frag it and experiment with placments after you have more than 1 frag to play with.