I am in need of a new slotted classroom mail center for filing graded student papers. The one I have now will not accomodate the large class I will have this year as it only has 20 slots, and I don't know where to buy a sturdy one that won't break the bank. Really good stuff has a cardboard one for $49.99 plus shipping, but I don't know how sturdy it would be for use over multiple years. Can anyone recommend where to purchase something for this purpose? I think I need something for around 26-27 students.