I don't buy singles, unless they are super charged like let's say a 4a side or something like that. However the only singles I have bought from Ayu are Surreal and Endless Sorrow, and just because I adore those songs.
As for Mirrocle World, the posters, the sleeve case, I was praying for a PV for Mirror, and I got both the PV and full version, + it's her 10th Anniversary so why not!
But unless she releases an amazing triple/quad A side next, I won't be buying it
And I think this single will sell anywhere from 170k to 200k copies in a span of 2 months