Drop the cost of Runaan's Hurricane

I play Varus quite a bit when I ADC, and as I was speaking to people about him early in my purchase of him, I was told "Yeah, Hurricane can work in some situations, but getting
with
&
is just a more effective combo. For the most part, I've taken that advice unless we were getting slaughtered and I needed Hurricane to hold off waves of minions from our Nexus.
Yesterday I was looking at the two items and I realized that Hurricane is far more expensive with a less beneficial build order than Dancer. I'm aware most players think that Hurricane is a noob trap 90% of the time, but I'm wondering what the rationale is behind the cost disparity with both the end result, and the build order being so one-sided. Unless the thought is "you buy this to prevent Super Minion onslaught."
Anyone know what the reasoning is? If there isn't one, shouldn't we reduce the cost of Hurricane or, at worst, change the build order?
(I have no idea if this is the right board. My apologies if it's not. Nothing jumped out at me for item discussion)
?