This 254€ is both ways including a bed in an inner cabin (no windows, 4 beds, air conditioned) and the transport for the bike. Just having a pullman seat is a few bucks cheaper. The later before departure you buy the ticket, the more you'll pay. We met people who payed 350€ for the same. Mr. Hardheader organized the tickets half a year in advance (thanks again!). Food and beer is extaordinary expensive on the ferry (0,3l can Heinecken = 4,50€, simple pasta ~ 10€), so think of bringing your own food and drinks.