they get cheaper out of season but not sure as to the Liverpool boats (I always fly) - try the farecracker from Liverpool airport via Manx air - experience (my mother lives in Warrington!) is that spending 14 pounds on taxi is easiest but cheapest is train or even the bus to Liverpool and then the 60c bus(I think that is bus number - the express coach was discontined a year or so ago) but allow 1 hour for the bus journey + a wait of upto 30min as the service thro to airport is only every 30mins. - contact me privately if more help required