To be honest, I don't know. I assume it would be relatively easy, just because you won't change boundaries. Even in the case of the ballot, instead of making an X, you'd do 1, 2, 3, 4. There will be more entailed in the counting.
I think it would be simple, in that sense. If at some point there was a partial proportional representation added, I don't know how much it cost to redraw the electoral boundaries the last time, but it might be the same amount for a new system.
Just don't lose the opportunity now. At least walk away with something, and this is a simple system that I think improves our system over first past the post.