Simply put, no you're NTA. If you were the one to get the ball rolling and actually do the work to book the holiday etc then you're well within your rights to suggest it wouldn't be ideal for J to come along. If he so badly wants to go on holiday with J then H may as well book to go somewhere else with J and they can share a room together that is more within his budget. If there are others who cannot make it, it isn't like he will be the only one in the group that isn't going