The primary function of a personal trainer / nutritionist is not the advice they give, but that they force you to show up at the gym and keep track of what you're eating. It's 90% outsourcing of willpower and 10% knowledge.
If you're treating that as their primary function, you're just throwing away money, tons of money.
If you decide you want to work out and eat right, take responsibility for it and truly make the personal choice. Or buy a couple of self-help books to learn some techniques. E.g. The Power of Habit. It'll be orders of magnitude cheaper.
This argument is a bit self defeating. You can easily replace the information a personal trainer gives with a standard training program and YouTube videos that show proper exercise form. You cannot easily replace its willpower function with a book.
