Estimate the cost of a language course.
A language course costs tuition plus the materials and fees that come with it, and quoting only the per-lesson price hides a meaningful share of the total. Cost per contact hour is the figure that makes courses comparable, because lesson length varies from 45 to 120 minutes between providers — a cheaper lesson that runs 45 minutes can cost more per hour of teaching. The non-tuition share flags courses where enrolment and certification fees are a large part of what you are paying.
Course total
Total = lessons x price per lesson + materials + enrolment and exam fees
Unit costs
Cost per contact hour = total / (lessons x lesson minutes / 60)
Per hour, substantially — often a third of the price. Per unit of progress the gap narrows, because one-to-one time is all speaking practice, so compare cost per hour of your own speaking rather than cost per hour of class.
Yes, if certification is the point of taking the course. Standardised language exams commonly run 150 to 250 and are usually billed separately from tuition.