1. Whenever. Having no regional pricing was one of GOG's two clear, specific principles and giving up on it will never be acceptable for me. And while discounts can't be made fair, what mainly interests me is whether a game has anyone pay more than the base price, even if that doesn't include my region (though for some time now we're getting the hiked up Eurozone price too, because, you know, "market realities" say we're darn wealthy over here).
2. USD makes for clear comparisons for everyone. If you can add both (not that we're using the Euro), sure, but USD prices for everyone is a must, to be able to compare.
3. History can't hurt, but if you say it's that much more work, it's fine without.
4. *checks SteamDB* So it has current regional price in regional currency, current regional price in USD, difference from base price in percentage, lowest recorded price in regional currency and highest discount as percentage. One thing I don't see is lowest price in USD and will keep saying that prices in USD need to be everywhere for comparison. Otherwise, all of it is useful but, again, could do just fine with doing it MaGOG's way, only offering the prices in USD for each region.
5. Basically looking for a source that's up to date again for this after MaGOG went into legacy mode in protest against GOG betraying one too many of their values, so what's available there, which in terms of regional pricing means the price in every region (as per the region matrix listed) expressed in USD.
Are you not aware of the "Fair Price Package" or am I missing something? You should never pay more than the US price.
The package doesn't mean you don't pay more, it means you do pay more if your region gets a hiked up price, the publisher gets those extra money and GOG offers them back to you as store credit, in the currency you chose then, and you have to use it within a year of last getting some store credit in that currency to make another purchase from GOG in the same currency. That's not "not paying more" in the least and, either way, doesn't make the behavior itself any more tolerable.
I don't know if it's possible, but an adjusted regional price that takes into account the fair price compensation (the funds added to your wallet) would be optimal.
Regional price minus fair price package should always be equal to base price. If it isn't, it's a bug (usually resulting from a price drop where the base region, which isn't the US one actually, wasn't changed) and they should be made aware.