EBay search for rv windows all the time. A bunch came up that were the same, and the right dimension to fit between the bus ribs that I wanted to place them at. (The ribs have varying dimensions between them)
The windows don't have trim rings which makes them much cheaper. This means fab your own rings or fasten externally. Since the wall thickness is 3.5", there are no trim rings that deep so its fine.
These particular windows were about $55 each + a bunch of shipping cost. Pricing will vary a lot.
I'd suggest keeping an eye open long term, and try to match stuff like the shade and manufacturer where possible.
Originally Posted by Docsgsxr
Where did you order them from and what was the cost?