I'm really of mixed opinions on this for a couple of reasons. Yes, it obviously saves money if that's the purpose, and of course you would do that. Does it cloud the issue? In my experience, I would suggest it did. There were two horses in the race fighting all the way along--the candidates to be noticed and the parties to be noticed. The other side was the education of the electorate to understand the second ballot they were going to receive. We certainly noticed that when I was trying to compete to get media time, to get exposure for the question itself.
So I believe, yes, if you wanted to be single-focused and your primary objective was the referendum to get a clear answer from everybody. Is there a fear to that? Of course there is. I would guess, and it's purely a guess, that the turnout would not have been nearly as good if the referendum had been presented by itself. I think it brought more people out. But then that's the interesting part of our democracy: we get to either vote or not vote, unlike in Australia, where it's mandatory.