This national pricing leverage is a big part of why drugs are cheaper in countries with national price setting. Socialized medicine is actually less of a factor in this space. What matters is whether a single entity has the ability to set prices for the entire market (or a sufficiently large slice of it).
https://pharmaphorum.com/news/kadcyla-set-regular-nhs-fundin...
A lot of European countries do a health technology assessment to determine the cost effectiveness. If it's not cost effective, they don't pay for it.
Glybera was approved in the EU and Germany pays for it and it costs $1M.[1] Of course, very very few patients have or will be treated with it.
[1]http://blogs.nature.com/tradesecrets/2015/03/03/1-million-pr...