I'm actually going to speak more on my own personal opinion on the referendum bit, coming from my background of political science. I think that we shouldn't be putting a price on democracy, first and foremost. I think that's very dangerous, and democracy is one of those prized institutions in our country that we should value. Putting a price tag on it and being scared to do something because of the price is worrisome.
When it comes to doing a referendum, I don't think it is such a bad idea, but I think with the lack of education and how hard it is to educate during a referendum period, what you would have to do—and I don't know if this is even legal to do—would be to keep your options to solely the systems you'd like to change to rather than include first past the post.
The government has a mandate to no longer have first past the post, so I think you can make the case and the argument that, if you're going to do a referendum, on that ballot should be the systems you'd like to see implemented rather than the old system.