King
Be careful though, because I believe that the concept of buying the commemorative coins at face value is limited to the release date. For example the next 5€ isn‘t until September, and often sales of older coins they have left in stock are sold with extra costs added to them. Just don‘t expect to be hoovering up every commemorative coin for the last 5 years at face value.
This information is incorrect. The Bundesbank does not place surcharge on older coins. However, they are also not a coin store. Usually you can get the 5 and 10 Euro coins for a few weeks after issue date, once they run out, you don't get any, unless you are lucky and someone cashes in a collection, which happens frequently (they keep the silver for melting, but if you ask for older commemorative coins, they hand out what they have in stock at the desk, but they do not keep it there forever, they are destroyed after a while as well). 2 Euro CC have a higher mintage and might be available for a few months after issue date in rolls or single pieces (returns are mixed in with the change, so no use asking for older ones that they don't have at the register).
Also: Cash only, they don't accept cards there.