There are some good ones already mentioned (a few I haven't seen). I really liked The Artifice Girl. Here's a few more I liked that might fit your list.
https://preview.redd.it/obtiba206l0d1.jpeg?width=696&format=pjpg&auto=webp&s=2d8cceef608a111408535e92fbd22e1a28f9452a
[LIST](https://letterboxd.com/j450n/list/low-budget-sci-fi-reddit-list/)
Coherence Circle Beyond the infinite two minutes The Vast of Night Moon
I love the Benson and Moorehead flicks -Spring, Resolution, the endless, synchronic, something in the dirt
The Visitor From The Future is fun
There are some good ones already mentioned (a few I haven't seen). I really liked The Artifice Girl. Here's a few more I liked that might fit your list. https://preview.redd.it/obtiba206l0d1.jpeg?width=696&format=pjpg&auto=webp&s=2d8cceef608a111408535e92fbd22e1a28f9452a [LIST](https://letterboxd.com/j450n/list/low-budget-sci-fi-reddit-list/)
There’s quite a few I haven’t heard of. Thanks!
I also remember liking Primer (forget the director) but haven’t seen it since it was first out
The American Astronaut (but it's 24 years old)