Recently I got a message from a junior level designer, reaching out for help with pricing a landing page design job. It's a very common question that I get, pricing being the burning issue with less experienced designers, perhaps it's the biggest issue they have overall — or at least they feel this way.
My standard answer to this kind of question is as follows:
Hi X, if you don't know how much to charge, then let that not be of your concern at the moment. Take the job, do the best you can, and ask the client what they would be comfortable paying for it.
Take that amount as a reference point for future jobs, and try to charge slightly more each subsequent time you do a similar job. At some point people will start saying no, and then you will know that you are at the limit of what the market is willing to pay for your services.
Going forward, start making efforts to increase that figure however possible, e.g. by expanding knowledge, positioning yourself better, marketing, etc. Best of luck, cheers.
This might sound harsh, but it's how I believe it should be. And to answer other questions you might infer from this post right away:
The only reason I am posting this publicly is because people keep asking, and I think it can help others in a similar situation. Please feel free to ask any questions you might have, I'd be glad to help!