Take the train to Berlin
When is it worthwhile to travel to Berlin by train?
If you book well in advance, you can book an ICE to Berlin for as little as €20. There are good connections from Hamburg, Frankfurt am Main, Munich, Dresden, Hanover and Cologne, for example. Early bookers also have the option to buy group tickets and thus pay less.
Another point that speaks for the railways is the Deutschlandticket. If you don't have too far to get to the capital and regional trains are also an option, this is a very good way to travel to Berlin for comparatively less money. The ticket can also be used for public transport within the city. It is best to ask at a parents' evening whether some of the children have the Deutschlandticket anyway. This means that the trip to Berlin does not even incur any additional costs and the budget can be used elsewhere.
Getting to Berlin by bus
When is it worth taking the bus to Berlin?
A private bus has the advantage that you can be picked up directly at the school. This is particularly useful in more rural regions, as public transport connections are often inadequate. Parents would have to bring their children to the nearest train station or possibly directly to the larger city. That can be very cumbersome.
You are also more flexible in terms of time with the self-rented bus, as you can determine a departure time yourself. And if a child does arrive a bit late, the whole class won't miss the train right away.
Another advantage of hiring a bus company is that only your own class or different classes from the same school are on a bus. No child can get lost while changing trains and entertainment programs on the bus trip do not disturb other passengers.
A coach usually has a fixed capacity of around 30 to 50 seats. Bus companies therefore often have fixed prices for a bus, regardless of the exact number of students. So if you are not on a school trip with the whole class, but only with an elective course, for example, it is therefore not always worthwhile to ask for a tour bus. However, it is also true that prices can vary significantly depending on the distance and federal state.