I’ve had them for a really long time, so I was just wondering

Not very rare. The helmets are also newer versions, so they aren‘t even from the early classic space sets, and pretty much all classic spacemen are common.

Actually, I never got these sets myself, my dad actually had a few back in some old place, so I don’t even know where they came from

I don't really know, but i do have those minifigures.