A personal trainer can be beneficial. It was just too expensive for me.
If you are a beginner and don't know much about gym equipment or you need motivation,/accountability, a PT is a must.
If you are well familiar with gym equipment and exercises and you are committed and motivated on your own, a PT might just be a waste of money.
A good idea is to work with the PT for about 3 months. After those 3 months, you will have a good idea about what to do and you can then decide if you want to continue usinh her service.