Decisions like this are never easy, especially if you do not have much spare time, or are on limited budget. If this applies to you, my advice would be to firstly give serious thought to the questions:
• How much do I want this job?
• How good a job could I do if I wrote the CV myself?
• How much time can I spare writing the CV?
• How much money can I afford to invest?
If the answer to the first question is “very much indeed! “ and your answer to the second question is “probably not that good “ then I suggest that really you only have one viable option and that is to invest. And what you invest in really depends on your budget.
More to follow…