Well, here in the USA, two people can walk into the same car dealership, use the same salesman, and not pay the same price. While I do understand that the folks in the EU wonder why some countries pay twice as much than others for the same product, it is what it is.
Ah well, with all the snow and cold here in the Northern Hemisphere, we seem to be engaged in a time honored game of complaining about things we can't change.
At least until it is warm enough to go out and take some photos.
If you look at Europe you see a maze of nations with different tax tariffs and price differences. Cars are heavily regulated. I can not buy/import a car from, say, Sweden without going through a long process which ends up with that I have to pay 30,000 $ in taxes. At least.
Add then different prices on cigarettes, booze and beer due to different tax tariffs. Or different prices of pork meat, beer or cheese due to different regimes regarding agricultural subsidies.
Borders can differ from hardly any control at all. Like between Norway and Sweden. Or with long cues of people where everybody is checked. But where the narcotics smugglers drive pass the whole cue and drive across the border with hardly no hindrance. Like between the Baltic states (the equaliant to Central America).
Take beer. A carton with 24 cans of 0,33L costs 'about' NOK 500 (ranging from 480 to 520) here in Oslo, Norway. The same carton costs 'about' SEK 300 (NOK245) in Sweden, which is one hours drive from here. The same carton costs DKK 200 (NOK 220) in Denmark. But; hold on your hat: The same carton costs € 6,80 (NOK 55) in Flensburg, Germany - as long as it is German brands. We are allowed to take 'one' carton per adult person across the border to Norway, while the limit when crossing the border between Germany and Denmark and Denmark and Sweden is practically unlimited.
Taken then pork meat, cigarettes, booze, petrol etc. etc. Environmental organisations argue that a harmonisation of prices/taxes only here in Scandinavia would reduce traffic "considerably".
