A nerdy hobby for someone who likes coffee is to roast your own coffee! I don’t know about European outlets for green coffee beans but in the US there is a group of hobbyists, https://www.greencoffeebuyingclub.com/, that purchase coffee in bulk and then distribute to members at cost + shipping and some nominal fees for bags/equipment associated with distributing the beans. There is also a well-known commercial outlet, https://www.sweetmarias.com/. There are many simple ways to roast coffee ranging from a hot air popcorn popper to a metal dog food bowl and a heat gun as well as commercial home roasting equipment.