I would argue that if your company has 50 people, you should already be budgeting for infrastructure, and the sudden jump in costs shouldn't take you by surpris

I would argue that if your company has 50 people, you should already be budgeting for infrastructure, and the sudden jump in costs shouldn't take you by surprise. And $50/user/yr is still a hard-to-beat price if you're making good use of the package.