How Much Would an Umbilicoplasty (To Remove the Hole Left by a Navel Piercing) Cost?

I got my navel pierced about two years ago. I liked having it for the most part, but having metal bits sticking out of my stomach got to me after awhile, so I took it out about two to three months ago. The hole has gotten smaller (was 14g, now about 16/18g), but having been pierced at an angle, it doesn't seem like it could fully close up in its own. So that brings me to my questions; how much improvement would getting an umbilicoplasty make? And how much (on average) would one cost?