If you can afford level III get that ,when level XII comes out get that and so on ,you can't put a price on your internal organs.... Well actually you can but you can protect yourself for a fraction of what a kidney/liver or couple feet of intestines cost.
You asked
Hope that helps.
PRICE OF A DECENT LEVEL IIIA VEST $700 to $1000
PRICE OF PROTECTING YOURSELF FROM A $1 DOLLAR 9mm JHP AND AVOIDING THE FOLLOWING TRIP TO THE ER
PRICELESS!!!