Hello dear!!
Thanks for the question and provided information as well.
Looks like you could benefit from a butt augmentation with implants, but unfortunately, without pictures, it is very difficult to give you a proper answer.
The average cost varies a lot depending on the clinic, the country ...
While we want to have a closed wound, closing them at this point may lead to further complications. With an open wound it is technically "dirty" in the sense that there are contaminants and bacteria on it. Local wound care it often the best option.