If I want to sell you a window, I need to know a lot of things:
whether it's a new construction or replacement window
whether it's a slider, double-hung, casement, awning, fixed picture or whatever.
if the window has an arch top.
the size of the window
the kind of glass
whether the unit has an argon filling
if it's tinted
if it has grids, and the style of grids--internal, simulated divided light, whatever
By the time you're done, Simonton could make five thousand different windows and every one of them would cost a different amount.
So! What they do is give the dealer a pricing book that says how much a particular size of a particular style of window costs, and you add the upcharges from there.