Ha, nice scheme. To go to one place, get someone killed, then got to someone related to killed person and get som revenge going, repeat until everyone involved are dead.
The natural course is not to buy the services of the fellow who provided one's enemy with the means to kill one's wife and child. It is to kill both that fellow and one's enemy, even if the methods have greater risk of detection.
@Tanterei The idea of a notebook that kills whoever's name is written in it is the core conceit of Death Note. It's not a bad series, but it takes a nosedive about halfway in. This case seems to be deliberately ripping off Death Note, either as a red herring or a lazy writer (I prefer to believe the former)