What is most cheapest way travel on Finland ? A: BUS

List budget bus firms

OnniBUS http://www.onnibus.com/
ÅBus ÅBUS
KoivistonAuto http://www.matkahuolto.fi/
ExpressBUS http://www.expressbus.fi/
Matkahuolto is ticket & bus freight firm that sells different bus companies tickets-
Pohjolan Liikenne http://www.pohjolanliikenne.fi/
Savonlinja-yhtiöt http://www.savonlinjat.fi/

Best way buy bus ticket is buy it on WEB store. Even bus may have Visa / MasterCard sticker on window may foreign cards has problems on bus ticket machine. And some companies CARD is
king and cash worthless, e.g OnniBUS accepts only cards on bus, no coins, no notes.