They go to Germany for cheap pilsner. The locals don’t consider it any extra beer.
Shopping abroad in Germany for the Czech premium brand Pilsner Urquell is still a luxury for Czechs. A bottle is up to ten crowns cheaper than here. In contrast, other neighbouring countries have a different pricing policy, according to Aktuálně.cz. In Poland, Slovakia and Austria we pay the same or more than at home. Roughly 26 to 29 crowns per pint in a bottle. Chains are currently enticing beer drinkers with an unprecedented discount on the Czech premium brand Pilsner Urquell. Only very briefly does the Czech price come close to the price at which Pilsner and some other Czech beers can normally be bought in Germany without any discounts. For the neighbouring beer superpower, the “Czech original” is simply not a fancy drink. In short, a normal price.
Source https://aktualne.cz/v-nemecku-za-lahev-o-10-korun-mene-pro-tamni-pivare-je-plzen/