The insurance claims representatives interfacing with customers follow a script and will often select car price comparisons lower than your specific cars value. In the US, the insurance company should also pay exactly what the equivalent replacement car is worth, but if the customer isn't paying attention it leaves room for them to profit. If the customer complains with supporting evidence, then the insurance will act in accord with the law, but if the customer is unaware or doesn't care, then that's a win for the insurer.

I imagine similar situations occur in Austria or Germany, wherever people and profit are involved really.