My bus is a 1995 and almost all of the double pane windows had bad seals when I bought the bus a year ago. The windows were made by Hehr and just the glass replacement alone would have been over $400 per window. I got new double pane windows from Motion Windows for less than $400 each.
The price differential between single and double pane windows wasn't much, so I went for double pane.
I seem to recall that Creation Windows won't sell direct and refers retail customers to DMC Company (
www.dmcco.com). I tried all kinds of window places and Motion Windows had the best prices.
Brian