Perhaps repair instead of complete replacement can be done? Windows, as a total, are almost the most expensive change that can be made. Plexiglass can be polished to remove fog and scratches and other parts including cranks (and parts), trim, etc. can be purchased. Check out the Helpful-Links section for vendor help here: Windows and Window Parts
Here's another source for windows, it will be in the Helpful-Links later:
They're located in Hillsboro, Oregon. Do comparison shopping!