it's used to be 50-70 pulls,but if u cant get a rare by 100-120 that means they changed the drop rate as none ever reported pulling a rare at 100+ before 3.0.so i think they changed the drop rate ,so people would spend more.this can be due to the fact that they were very slow with adding jinchuriki treasure in the game,so most people even free to play had enough scrolls to get a super rare without spending anything on seals.that dropped their income by a lot since most whales would go deep in kage treasure to get a super rare.