Seven seats car seems to address a very small niche.
I don't think people buying Teslas will start carpooling any time soon.
But yes it is a niche, but not small. There is a lot of 7 mvp cars where I live, Vauhall Zafiras, XC90s etc. And in most of these the third row seats are cramped pop up seats.
A Model X should come in around $80K, assuming it is just a bit more than a comparable Model S, which starts at $70K.
I think one of the things the Model S has done is get someone who might spend $50K on a car to spend quite a bit more than otherwise, because of its coolness factor. I think the Model X will do the same thing, and get people who would otherwise drive something less expensive (in the $50-60K range) to reach upwards to $80K or so because of the cool/wow factor.
I've got a Pilot now; and like it. I need to see the X in person. Right now the falcon wing doors are not a selling point for me and lack of rear-seat entertainment system make it less compelling than it otherwise might be for the money.