Pricing creative services is an individual's game. If you could take any creative service/product and find out what people/agencies charge, you'd find the difference between the lowest and the highest is 10,000x (take a logo design, the lowest example might be $100 and the highest $1,000,000).
So the real question shouldn't be "what would you charge" but rather why do prices for the same services vary so much? And how can I change what I charge?
The most obvious things are easier to control.
Knowledge - Often in the form of experience but not always. You don't have to spend years on something to become an expert (though it helps) you just need to know what to learn to understand something at many levels and from many angles. Every single person can always know more, so start learning.
Quality - Somewhat subjective, but in general the better the quality the higher the price tag. Any one of us could always improve the quality of the work we do by spending more time on it and fine-tuning something. So, this is an easy one to start with.
Your market - Now, not every single person in the world has the same needs or desires. Not every single person has the same access to money. So naturally, some people and some businesses are willing and do spend more money on certain things. So, always look for ways to work with a higher yielding client base.
How should I work out my base?
When working out what to charge for a project you need to consider 3 figures.
1) Your costs: How much time/effort will you spend + any additional things you need to buy to complete the task (such as a premium plugin).
2) The value: what is the impact of the work you are doing? This could be ROI, this could just be how much someone would be willing to spend for you to help them achieve a goal.
3) The price: This is the actual figure you present to a client.
When the price is higher than your cost but lower than the value you provide, this is a good deal for both parties involved. If the price or value is lower than your costs, this is a project to pass up.
If you take the approach of understanding what your base price should be, this will allow you to start having conversations around the value of what you offer. When the prices mentioned are lower than your base price, you simply walk away from the project.