So how many orbs of chance does it take?

I had chanced this back in september i beleive,after pickimng a white siege axe BY ACCIDENT,so i said what the hell,spend a chance on it.Since then i have been systematically chancing bse items with no results.

i used roughly 5k chances since now and hit an andvarius and a lioneyes. in the same time i 6l 7 items, 4 in this league. 3 of them in less than 10 fuses, 2 in roughly 50 and 1 in 150 and 500. its just luck or bad luck.

also the droprate of the base item stands in no connection to the unique type of it. it used to be like this but that was changed ages ago.