I plan to take a train from Dusseldorf Hbf to Koln Hbf on the Saturday during the Easter weekend. The schedule on bahn.com shows the prices for ICE and IC trains but no fare information for RE. Since regional train is slower, I'm assuming that it's cheaper. Does anyone know how much it would be and will there be so much demand that it's difficult to buy from the ticket machine on that Saturday? Oh and does the ticket allow transfer to another transport like bus or subway? Thanks in advance.