This highly depends on what you're commissioning.
I take into account the amount + quality of materials used (clay, glazes, etc.), amount of time needed to complete the project, and potentially shipping prices if need be although I prefer being able to have an in person exchange for the commission at the moment!
Furthermore, I do require half of the commission to be paid up front and a fee if you pull from the commission after I have completed it. This will be discussed when we chat about what you're interested in commissioning as I have a contract that we will create in part together, detailing these fees and requirements.