They use regional pricing for some games, but they added a sort of "fix" giving you the difference as a "discount" when you'll buy another game.
At one time I understood and accepted, even championed, their "discount" solution as a lesser of two evils: if they wanted to get on some of these bigger names and grow as a distribution platform they needed to accept these big companies terms, at least for a while. In the perfect world they could just say "naw, we don't want your massive budget game that's going to bring us lots of money, we're happy making small money on old games and indie titles" but that's not the world we live in, I don't begrudge them that: sacrifice a little of yourself now in order to be stronger for it later.
But I just recently learned that it's not just big names anymore, they're putting a lot of new indie games on regional pricing, small companies that should be accepting of whatever terms GoG gives them for distribution until they can make it to Steam.
None of this would be a problem if not for the fact that they made non-regional pricing a key part of the platform in the early days. They had ad campaigns and everything, "because $1 != 1€", it was a fundamental part of their business and the reason a lot of people signed up. For them to now decide that it isn't a part of their vision at all (as opposed to still being part of their vision, just something they need to regretfully compromise for now) is a betrayal. I bought a lot of games from GoG because I believed in what they were doing, often whether I had any interest in playing them or not, and now I find out that where they were going is not where they said they were going, and if I'd known that I would have saved my money.
I mean, the whole "password protected installers" was getting dangerously close to DRM territory, how much longer until they decide that's not part of their future, too?