The only thing I can recommend is calling around to your local window places and have them come out and give you an estimate. And call several, one place wanted over $800 per window (but they would last 50 years, or so the salesman said), the next place it was only $300 per and came recommended by friends. Installed, with actual trim (not the 1" trailer trim). The local DIY stores did not have windows that fit, and the only trailer store in the area (that's one, over an hour away), wanted nearly the $300 per window WITHOUT the installation or trim. Good luck!

Mil

Home Depot sounds good. The windows you installed ..did you install them from outside into the opening?
Thanks for the reply.

On the one I did, the original windows (aluminum frame) had flanges with screws on the exterior. It has aluminum exterior siding. I bought new vinyl single-hung windows with the nailing flange same as for regular houses. Used the Permacaulk ribbon, #10 x 1 stainless steel screws, then the PVC clad aluminum coil stock to cover all those screws and the flanges. Used the Permacaulk under the aluminum trim too. Piece of trim across the bottom first, sides next, piece across the top last. I borrowed a trim brake from a friend and the house now looks far better than when new. Tan exterior on the home and I used dark brown trim on the windows. The trim pieces held with #6 x 5/8 stainless steel tapping screws.

That sounds just like the ticket, bus driver. Now just have to find the right sizes. I had already been looking at Home Depot,and I did note some vinyl windows with the flange around the edge.
Thanks

There are several options for window replacement. $200 to $300 per window is not unusual in most cases (uninstalled). There are some companies that will custom make the window to fit into the mobile home window opening, but they are a bit pricier than "off the shelf" windows.

When replacing windows, it's best to move up to the vinyl or vinyl-clad "house" type window, and many are available in a "slim" casement, which matches older Mobile homes that were framed as 2" X 3" rather than the current standard of 2" X 4" studs.

You will need to specify REPLACEMENT, rather than New Construction, as the replacement windows come with an exterior nailing flange, where SOME new construction windows do not.

When buying the windows, find one that is slightly smaller than the rough opening of your existing window. This way, you can re-frame into the casement, or shim the window into the opening, rather than tearing siding and sheetrock out to widen the window opening. Run a wide bead of Lexel (or other moisture-proof caulking) where the flange will meet the existing siding. The best thing to use for nailing is galvanized hand-drive roofing nails. They have a thin flat head that flushes better to the flange and won't stick out as far as screws will. Since they're galvanized, they won't rust if moisture were to get in.

Use a window wrap (6" vinyl tape covered with foil) around the nailing flange, then apply your trim and caulk with painter's caulk.

AND....be sure to use a level to make sure the window sits plumb and level in the opening.

Just in case you haven't yet bought those windows at Home Depot, try the Window Depot.

Here is a link that might be useful: The Window Depot

"You will need to specify REPLACEMENT, rather than New Construction, as the replacement windows come with an exterior nailing flange, where SOME new construction windows do not." I am not a window expert by any means. But this statement above seems to be the opposite of what I have experienced. I used windows for new construction on my job and did have to order them made in special sizes. SuperSeal is definitely not the very finest of windows, but was the only source for two special sizes I needed and the prices were very reasonable.