Well, as I said the price point is my personal thought. So they could easily make it $99.99. If they want to compete with Apple TV that would be a fair price.
Though, $150.00 wouldn't be an unreasonable price, if the system came with 64 GB hard drive which is up-gradable, a controller, 1 GB RAM, Wifi and Eithernet port, a pre-installed game or two. Heck if they can pre-install Halo 4 or a version of Halo 4 multi-player then you have yourself a winner.
Of course I would rather have a lower price point. But, I am thinking about what MS might try to price it as, so that it can make a profit...and I think that price would be reasonable.