Thanks a lot for the answer. As I understand it can be any number of registered users on server but only 20 registered users can work at the same time on server as "concurrent users", and the max number of such concurrent users is 20+20+150=190, right?
What will be the cost of these 190 concurrent users per year?
For 20 users it's 9,995 /12 / 20 = $41.65 user/month