I will be traveling by public transportation from Stockholm Central Station to Skinnskatteberg, and then back to Stockholm a few days later. Will I be able to easily buy a ticket at the station on the day of my travel, or is it best to buy in advance? I would buy in advance, but I'm not completely sure of my return time from Skinnskatteberg. Or, if I bought a ticket in advance from Stockholm to Skinnskatteberg, would I be able to easily buy a ticket at the Skinnskatteberg station on the day I return? Thanks for any advice.