This is a really difficult question to answer.. but in MNSHO .. I would respond in this manner:
Why am I developing my course? For education, fun, profit?
(I have serious reservations about adding a profit motive into education, but in this incredibly mecenary modern financially oriented economy, even I must be forced to accept that I need to cover the costs incurred.)
If for fun then the charge is obvious, nothing. No-one will object.
If purely for education then again, nothing. Why charge at all?
Robert Heinlein wrote, in "The Moon is a Harsh Mistress", that education in Luna is based on if someone has a usable skill then they can figure out what they think people will pay and put up a sign. I do not accept that as a reasonable premise even if there is a shortage of formal education structures and no collective pool of funding, ie taxes.
So does your question relate to that? No alternative educative process available and no public funding?
If there is an alternative, then look what they charge. Look at what they offer and set your price accordingly. Assuming your competition is a traditional classroom with lecturer and so on, you can reduce your fee by as much as 75% and still cover all your costs and make a tidy sum on the side. If they are online then that is another issue.
Alternatively, if there is no public funding then you will need to cover your costs. So what are your costs? Your time for creating the course, the equipment you use, the energy costs upload, administration and so on. Most organizations have some commerical rules in place for calculating their IT costs so you may be able to work out from there what your share of that would be.
The other consideration, if you want to look at it that way, is "how much does my course contribute to improving the earning capacity of the student?" If it is a core subject and absolutely critical, then you may say, about 1%, or 5%. So what is the annual income of a graduate and multiply it by that percentage.
The last consideration is how many students are going to enrol in this course in a year? It is a semester course, say, and in each semester I am going to have, perhaps 30 students, for the year. I divide the total of organizational costs, plus influenced income by 75% of my expected enrollments.
The equation would then be something like (Time + Organization cost + (Income * influence))/(expected enrollments * 75%.
In numbers it might be like ($2,000 + $1,500 + ($150,000 *2%))/30 * 75%
In short : $295.50 (rounded)
Note, this is a suggested framework. It covers costs this year and assumes that there is no ongoing involvement. If there is then that cost may also be included, your institute will probably have a predetermined figure to add that into their calculations of course. This number is also based in the reasonable expectations of earning capacity and impact of your course for graduates, and anticipated enrollments, of which you will have far more accurate data than is here. More enrollments decreases the time you reach the breakeven point, fewer enrollments, slows it down. If you use the course a second year, without much change, then you are making profit almost from the start.
Please be aware too, I only responded here to as it was an interesting intellectual, if simple, challenge that may help someone with a specific goal. The difficulty of these questions springs from the lack of relevant information given in the original commentary. I am actually appalled with the idea of turning it into a real world example of how to charge for passing what should be freely available knowledge from one generation to the next, but that is just me.