How much money for a design

Having taught a lot of students studying photoshop, corel, Ai. And when they work, they ask me how much it costs for a design, such as a logo or poster. Please share with some new entrants, new freelancers as follows.

Problem 1: When you value a product, it usually follows a common ground. Look at the person next to you to give the price (lower than the people).
Problem 2: You guys often compare with your working day at the company.
Problem 3: You guys go on “unlucky” when you are high and low.

Please … according to our experience, customers will follow the following formula:
[Experience] + [Working time] + [Device + technology] + [Visitor object] + [discount + relationship] = design price.

Share your freelancer experience

I just graduated from school and now I have been working for 2 months. I am also a freelancer, today I created this topic and want you and your brothers and sisters to share their experience of working with customers, each customer will have their own tastes and tastes. I can understand and exploit that information so that the process of working with customers is relieved when submitting products.
For example, they told me they wanted to design clothing shop logos or something. I hope you share your experience to help the new toddler enter the profession. Thank you