I've seen some people make DIY anamorphic lenses. Pretty darn impressive. I am just not sure that I could tackle something like that, despite everything else I've fixed, made, built, etc in my life. My other fear with a lens system is that it is yet one more complexity variable for my family. They are going to struggle with hitting a button on the remote to do a memory preset for zoom, shift, focus, and that is just hitting a button, not manually sliding a lens into place or back out.
There are definite economies of scale (but instead of being cheaper for more, it gets more expensive pretty quickly) to smaller vs. larger rooms.