I'm thinking right in between at $400. The advantage to setting the price that high is that not everyone will have it, so it'll still be cool because its unique. I think at the beginning, the iWatch will be seen as gimmicky, until it becomes a bit more popular
There is the possibility for multiple models/sizes, so that would change the price point up a bit. I'm thinking $300 on the low end, $450 on the high end.
I'm also thinking that they will probably do more then one model of the watch like a higher end around $400 and then possibly a cheaper one for $200 or so. But that's just off of rumors that I have read and seen.
Currently there will be two different sized model faces, a 38mm and a 42mm face with bands to match so I reckon pricing will be based on that just like the iPhone 6 and 6 plus.