Excellent article, but, if you really want to blow people's minds with the cost of training, you might consider that the customer is not only paying the learners' wages during the training time, but they are also losing the productivity of those workers.
If a worker is getting paid $50/hour. the organization should try to be making $150/hour as a result of their efforts, for a net value of $100/hour to the organization.
When that worker is in a class, he or she is no longer adding value. The organization is not only paying $50/hour: they're paying for the lost value the worker should be adding as well.
That lesson is really costing $200/hour per $50/hour employee.
Therefore, the learning experience you design had really better be worth it.