If you're in Dublin put it on Dublinwaste.ie's freecycle. [broken link removed]. Anybody who wants it will take it off your hands but you won't get any money for it. Although you will know that it least it's been recycled.
Last year I got rid of a bath, basin, toilet, kitchen sink unit, window and back-door. I would have had to get a skip to throw them out which would have cost me, instead I saved the money and they all went to people who were glad to have them - and who collected them from me.
Two things if you are putting up your bath on this site though - make sure you put it in the correct category, and also make sure you put up a picture (otherwise you'll never get inquiries)