French platform combines carpooling with cross-border price arbitrage in the EU
karlsnotes.com
karlsnotes.com
This shows that the EU still has a long way to sufficiently integrate its markets, despite free movement of goods having been established ages ago. Projects like this may help facilitate the transition to a more unified market.
Austria's high groceries price problem isn't due to a fault of EU market integration, it's due to the cartels that own the retail sector in Austria and milk consumers for all they're worth.
In other words it's a domestic self inflicted problem, that Austria can solve but chooses not to, not an EU problem.
The only problem is even with the data in plain sight, government regulators still don't do anything.