What has a Hasselblad lens got to do with benefiting or improving photography in this case? You should have cracking skills with even the most basic of cameras, AF or not. As tantalising as it may seem, slapping a flash-bang-whollop 80 T-Planar on the front of a 645N won't necessarily raise your photography to the nth degree and win you awards, especially if one's photography quality is thought to be lacking based on equipment, rather than foundation photography skills.
That — the skills, is where the money should be spent.