Oh! I forgot about They, aka Invasion from Inner Earth. That has to be the cheapest-looking movie I've seen. It has:
-A mysterious light, which is just someone just outside the camera's view shining a flashlight at a wall.
-A paper-plate space ship, shot in closeup, so close you can see the ribs on the plate.
-Another spaceship that looks like a Styrofoam ball & ring covered in aluminum foil. Also shot as a closeup.
-Amateur actors.
-A bunch of people running up-and down a street screaming, while orange smoke bombs simulate some sort of disaster.
-No real sets; everything's shot on location in a couple of cabins in the woods.
-A cheap synthesized rip-off of The Good The Bad & The Ugly's theme song.
Let's compare They to Plan 9 from Outer Space. Plan 9 had pro actors, decent stock music, actual sets, matte paintings, real (off the shelf) models, superimposition, and a cool sound effect for alien metal. They beats Plan 9 as the cheapest looking movie I've seen!
Again i think a color cheap mocie looks worse than a B&W one.
I will say at least invasion from inner earth had a few decent attempts at intelligence and thoughtful exchanges.
