I was thinking that too, the series will probably never pass the bar of the 200,000 thousand copies sold in first week. And well considering the other series in Jump ToC there is no way for it to suddenly become that big. It would have done so otherwise.
On another note I'm actually quite surprised by the sales Magico had. Back then the series had a lot of color pages in the first 40 chapters which showed it was popular but the first week sales for the volumes I found on the MH were these :
Magico #1 32,023
Magico #2 21,622
Magico #3 23,857
Volume 4 having roughly the same number and well it's actually a lot less than WT 3~4 first week sales. Intriguing. It looks like WT success resides within a long run and the ability of the author to actually make a really interesting story, contrary to most other series that start with a really interesting concept but end up burning out too fast
Maybe the same will happen to "Illegal Rare" (though I'll probably drop the series after c03 if it's as boring as c02).