Hard to say about the prices. Have you seen the new Explorer II? You can see on the Rolex website. Some people like the new hands some people don't. The important question is which version sings to you.
Not sure when it will hit the stores but am sure early prices will be high. Once the initial demand is over the price will stabilise. Based on past experience, the price of the out going model tends to go up as the stock dries up and stabilise.