Don't be discouraged by the lack of responses so far ^{[this topic has been viewed only 19 times so far]} and just to give you a general answer, you'll have a real chance in charging someone for a course ^{[and etc...]} if a similar one doesn't exist already on the internet for free or for a cheaper price than yours. In regards to your last question, that depends on the complexity of the problem ^{[don't expect others to answer it accurately]}.