The actual cost of the window is going to vary greatly across the board. The cost for one of their high-volume dealers is going to be different from a low-volume dealer, and different still from someone walking in off the street.
Those numbers mean nothing to anybody that doesn't work at the factory, but if you want a range, as a consumer you'll probably pay somewhere between $150 and $350 for one of their more common units.
If you are in need of service on that window, as Joe said, just call them directly if your original dealer is not around.
Edit: After looking again, I see that it has a bronze exterior. Expect the price to be on the high end of that range or even more.