I too was shocked and a bit offended that it was called a B movie. But the budget was a freaking measly $6.4 million.
That's peanuts even back in 1984.
https://en.wikipedia.org/wiki/The_Terminator

Indeed they accomplished a lot, an all time classic movie. Some of my friends were a bit critical about the stop motion not being very good in their opinion. But I just thought the movie was amazing.