There are two new Nexus phones available now, and that means the Nexus 6 is yesterday's news. Google has been selling the Nexus 6 at a reduced price for a while, but now it's over. The Google Store now says "The Nexus 6 is no longer available for purchase." It's the end of a very, very big era.
You won't even see the nexus 6 listed on the main phones page of the store anymore—you can only get to the listing via the direct link. The Nexus 6 is still available from other retailers like Amazon, which is selling it for $500 (32GB). That's what Google was asking for the Nexus 6 until today. It's been much cheaper a few times in recent memory as well.
It's unlikely that Google sold literally every unit it had left in stock, so be on the lookout for leftover phones to pop up on eBay and other retailers. Let's have a moment of silence for our dearly departed phone friend.