Was (cos some things changed - as Alexander lowered the costs to produce Common) the exact math
You cannot just compare only the Common once ... Silver Boxes do include Rare and Epic items.
Rare a lot and Epic sometimes
Compare their production costs as well.
With opening +1000 Silver boxes you get a very clear result how much % are Rares & Epics
So, doing the exact math (at the time when the base came out - yes Common are now cheaper as mentioned, Alexander made them cheaper), incl. the Rare and Epic items, the result was, Items in general (Common, Rare & Epic) from the Base were 7 times more expensive
And as mentioned as well ... now the factor may be 6 or 5 with the "new" Common costs at the Base
55.5 (periodically) hours ... exact math
That must be a joke - yes
That would be a +22% chance for a Legendary
And as said before as well, yes the Base has its advantages (chance for Legendaries, Extra-Gold, specific Items and Power Units Production), but it has as well a significant disadvantage ... the a lot higher costs of items to fuse
Again ... IF it would have only advantages, no one would ever ask for disable the Base ...
... "hundreds of accounts"