Why would you want to pay thousands of dollars to send your employees on some course for two days? If you sum up all the hours they waste at the course that's a shitload of important stuff that won't get done. How much can anyone learn at a course anyway?
But, let's do some more math. Say that your employees are on a productivity course on how to work or communicate more efficiently. Maybe it is about organizing one's work in better ways. How much more efficient can one get by attending such a course? 5 percent? Let's count conservatively and say that you only get 1% more efficient for a year after attending a two-day course on efficiency at work. Let's say that after one year the learnings are forgotten, or no longer as relevant due to changes in the organisation.
In Sweden, an average employee works 250 days in a year, 8 hours per day. That is 2000 hours. If someone gets just 1% more efficient, it means they will get 2000 * 1.01 = 2020 hours worth of work done if they take the course. The course costs 16 hours since it is 2 days long. So in other words it might be a very good investment sending your employees to that course, as long as you expect them to become at least 1% more efficient at their work. Worth pondering.