Whether or not the help is installed locally or just refers to an online help is usually an install option, in my experience. I haven't installed libreoffice in a long time because I don't like it, personally, but I think it's probably still an option. Maybe not.
If you don't factor in re-training costs, it's never a fair comparison. Training, however, doesn't take millions or even hundreds of thousands, of dollars and once your workforce is trained, new employees can always ask existing employees how to do something. There's a minor productivity hit until people are suitably comfortable/trained but that happens every time a new version of any existing software (MS or other) comes out anyway. It's the cost of doing business.
I think in the long-term, I think open source still wins but you have to roll it out properly and not just expect people to figure it out for themselves. That said, I've seen MS be very supportive and also seen the exact opposite from them. It all depends upon who you have on the other end of your issue and sometimes how much money it means to them.