The Titan X was released 3/17/15 and they've had that GPU power/performance since, for people that want/need the latest and greatest there bound to buy the best, especially when money really isn't an option. So those who purchased the Titan X (and maybe SLI) will probably wait for a Pascal Titan which i'm sure will be around the $1000 price tag and they'll end up getting that as well. When the GTX 780 6gb came out (I think it was around april 2014) the price of each of them was around $550. I ended up getting one around release date then a second around Oct 2014 and TBH I have been really happy with the performance but yea at the time it was $1200 worth of GPU's. For me though, the $1200 is worth it to have high settings @120FPS for a few years and if I have to dial the settings down a bit then its fine, i'm hoping this setup last till a GTX 1080ti or even when Nvidia Volta comes out.
As far as price goes, Nvidia still needs to stay competitive with AMD and I feel like the X80 series GPU's have been around $500 for the last few series.