You'd probably want to charge $10/year (once) rather than $1/month. It's still an easy choice for many people (of course still inaccessible for students in some countries).
Another option is to make deals with universities or schools for access for their students where they pay a certain amount per year and the students can all have access
Yeah, that would be a __lot__ of overhead. Not worth it. I'd instead focus on trying to find sponsors ("$100 / month allows us to give a free account to 100 students in X countries!")
