There are many consultants who will offer feedback and "edit" essays and the costs can range substantially (costs may also depend on how many "reads" you need). Because I work for a consulting firm, I will refrain from answering your question directly and instead offer some general guidance.
IF you plan to use an editor, please please make sure that this person understands who you are and what you are trying to convey. Admissions committees can tell when essays are not authentic and the idea that you hired someone to help you could risk your chance of being admitted. Having someone give you feedback and constructive comments is expected, having someone rewrite your essays is not. An Adcom can tell the difference.
SO, I suggest you look for a coach who can guide you through the entire process and help you create your own unique story. A good consultant will help you understand what the admissions committees look for, s/he will also help you understand your own strengths and weaknesses. You can then use this guidance to present yourself in the best possible light. This might be more expensive but is much more impactful (and truthful) than hiring an editor after the essays are written.
Obviously, after late nights of essay writing, it is important to have a second set of eyes look at an essay for things like spelling, typing errors, etc., but, hopefully a friend or family member will be willing to do this. If you are looking for more significant guidance, just be careful who you work with.