Sounds like you already have what you need. $200 seems pretty reasonable for a custom size solid wood door.

Well, the Lowe's door are out. Just a slab of wood. If we had a mid-century house it would look fine. I think it'll look completely out of place with what we're doing. Back to the drawing board...

Depending on your style or your budget, in our 1890's house, the odd sized doors were made with planks of wood and horizontal or X version brace across them. They are painted, they have the old time handles....smaller turn knobs, exterior door jams, and they work fine. This is upstairs in an addition that was made. The grandkids actually love them even more! It's just a door. Not a gold mine. Do what is most economical, even if it is temporary till you find the person remodling tearing down the old house with the doors that fit your opening?

Options that I considered when I needed non standard sized closet doors:

Custom exterior shutters.

Custom cabinet doors. Built out of 5/4 stock would be more substantial than the standard 3/4" material.

Cut down a hollow core door and add some 2.5-3" wide strips of 1/4" thick wood, strips of tempered hardboard, etc. to make a faux paneled door.

Find a local millwork shop. They exist in most cities of any size. They can make exactly what you want and they usually are not the sun and the moon.