cheap ferries to valencia



hi everybody,
does anyone know anything about cheap ferries to valencia?im going to ibiza for a month and i want to go to valencia for a day or two.
transmediteranea (can't spell it!) are expensive if you are not an ibizan resident.
baleara go to valencia too(well, denia with a bus from denia to valencia) and the cheapest i could find with then was 84 euros return.
one post i read suggested the site but it won't come up on my computer.does anyone know how much this company charges?
muchas gracias :D