Pay to see giant's causeway and such?

Hey Everyone, heading up to visit Belfast next weekend, my daughter is mad to go to Giants causeway, son wants Carrick a rede rope bridge. Is it really £35(family ticket) to go see each? Seems mad that these things carry such a hefty price to visit!!

Anyways genuinely can't wait to visit either way, staying in Belfast city, going to an ice hockey game, titanic museum and wander the city .

Any particular spots not to be missed?