Unless you're really shaky I wouldn't think you'd need VR in a 50mm lens, especially with a D750 where you can push the iso quite aggressively without much impa

Unless you're really shaky I wouldn't think you'd need VR in a 50mm lens, especially with a D750 where you can push the iso quite aggressively without much impact. You can get a 50mm f/1.8 for about £90 used, you can find the 50mm f/1.4 D for a similar price too.