If you plan to make ISK from ore or need to provide ore for manufacturing it is:
1. The hulk harvests far more minerals than any other mining ship (174% yeild increase from starting ships)
2. The hulk can 'tank' damage from most NPC rats, even ones in low sec, where other mining ships find this difficult
3. If you further your skill training to max skills the Hulk will bring in even more ore.
1. Several months in skill training
2. 100m-170m in isk for the ship itself
3. Further isk for ship modules (~10m isk)
If you wish to find out further details, I recommend reading The Complete Miners Guide