How Much Will Scar Revision Improve the Dented Surgical Scar on my Elbow?

Hi, I'm a 25 year old female and on the skinny side. When I was 6 years old, I had a botched open elbow surgery in a poor country (where I'm originally from). Now I have a horrendous elbow scar that is dented on the upper arm. This scar has affected my confidence very much. I now live in the United States. I saw on-line about W or Z-plasty suture to revise the scar. Would this work? How much would this cost? And would this be covered by insurance? I appreciate every advice I could get.