I will be taking the Ireland in 14 days tour October, and would like to rent a car at the end of the tour, in Belfast to drive to Dublin, but I can't find a car company that doesn't have a drop off fee of over $180. Any recommendations?
Since you are picking up the car in the UK (Belfast) and dropping it off in Ireland (Dublin) there is no way to avoid a drop off fee and $180 is not unreasonable. Dropping off a car in another country is always expensive.
Yes, this issue comes up often. As Bob says, the only way to avoid it is to re-jigger your driving to pick up and drop off in the same country. Between Dublin and Belfast, there's frequent and easy train service, so it's easy to get from one to the other to begin or end your rental.
dan Dooley (see post above) used Dooley Car Rentals and was happy with the service. I don’t doubt it for a minute.
Yes Norma, "one for Ripley," in the wonderful line from Some Like It Hot.
Blatant plugs aside, Dan Dooley does indeed often get good reviews. But using them won't address the OP's issue.