That explains why these two lenses almost have the same output on my D3200.
Image from the FF Promaster 19-35mm lens:
Image from the Nikon DX 18-55mm lens:
Both were shot at 35mm but for some reason the Promaster EXIF data spits it out as 20-34mm.
So in conclusion and CMIIW, you really are better off buying full frame lenses(especially if you have any interest in upgrading to FF in the future) instead of buying DX lenses, even if you're using it on an APS-C body.
The reason why I asked the question was actually because a friend was selling his DX 35mm f/1.8G for a bargain price(less than a $100 due to bro discount lol) and I was very interested in picking it up since I don't have a 35mm prime. But at the same time, I'm most likely gonna pick up a FF body come Christmas so I was a bit hesitant, especially since I kinda have no use for it right now(I'm also trying to restrain from GAS lol).