We will need to store our luggage in train stations at some junctures on our trip to Germany. I've never used the storage lockers. Do they take coins? Debit cards? There are 5 of us and we'll each have a 21" piece of luggage. Is it pricey?
When available, they take coins most of the time. There is also usually a change machine available. Pricey? In Paris last week, we stored 4 suitcases in two lockers for the day, for less than 10 euros each locker. Google each of the train stations that you`ll need lockers in, and search out the location of the consigned luggage / baggage storage.
Since there are 5 of you, find the biggest available lockers and stuff as many bags in each one and split the cost. Some stations also have attended storage but I've never found a need for that. Just make sure you have change as machines are not always available/functional.